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[PATCH v33 3/5] Subscripting for jsonb
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* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: erthalion @ 2019-02-01 10:41 UTC (permalink / raw)

Subscripting implementation for jsonb. For the sake of code reuse, some
parts of jsonb functionality were rearranged to allow use the same
functions for jsonb_set and assign subscripting operation.

Reviewed-by: Tom Lane, Arthur Zakirov
---
 src/backend/utils/adt/jsonb.c       |  27 ++-
 src/backend/utils/adt/jsonb_util.c  |  76 ++++++-
 src/backend/utils/adt/jsonfuncs.c   | 325 ++++++++++++++++++++--------
 src/include/catalog/pg_proc.dat     |   8 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   2 +
 src/test/regress/expected/jsonb.out | 233 +++++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  68 +++++-
 8 files changed, 632 insertions(+), 110 deletions(-)

diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 1e9ca046c6..f66642def3 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -1134,23 +1134,34 @@ to_jsonb(PG_FUNCTION_ARGS)
 {
 	Datum		val = PG_GETARG_DATUM(0);
 	Oid			val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
-	JsonbInState result;
-	JsonbTypeCategory tcategory;
-	Oid			outfuncoid;
+	JsonbValue *res = to_jsonb_worker(val, val_type, false);
+	PG_RETURN_POINTER(JsonbValueToJsonb(res));
+}
 
-	if (val_type == InvalidOid)
+/*
+ * Do the actual conversion to jsonb for to_jsonb function. This logic is
+ * separated because it can be useful not only in here (e.g. we use it in
+ * jsonb subscripting)
+ */
+JsonbValue *
+to_jsonb_worker(Datum source, Oid source_type, bool is_null)
+{
+	JsonbInState		result;
+	JsonbTypeCategory	tcategory;
+	Oid					outfuncoid;
+
+	if (source_type == InvalidOid)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("could not determine input data type")));
 
-	jsonb_categorize_type(val_type,
+	jsonb_categorize_type(source_type,
 						  &tcategory, &outfuncoid);
 
 	memset(&result, 0, sizeof(JsonbInState));
 
-	datum_to_jsonb(val, false, &result, tcategory, outfuncoid, false);
-
-	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
+	datum_to_jsonb(source, is_null, &result, tcategory, outfuncoid, false);
+	return result.res;
 }
 
 /*
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 5a09d65fdc..f46a2828b3 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -21,12 +21,16 @@
 #include "common/jsonapi.h"
 #include "fmgr.h"
 #include "funcapi.h"
+#include "executor/execExpr.h"
 #include "lib/stringinfo.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
+#include "parser/parse_coerce.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/hsearch.h"
+#include "utils/fmgroids.h"
 #include "utils/json.h"
 #include "utils/jsonb.h"
 #include "utils/jsonfuncs.h"
@@ -460,18 +464,22 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
+static Datum jsonb_set_element(Datum datum, Datum *path, int path_len,
+							   Datum sourceData, Oid source_type, bool is_null);
+static Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -486,6 +494,15 @@ static void transform_string_values_object_field_start(void *state, char *fname,
 static void transform_string_values_array_element_start(void *state, bool isnull);
 static void transform_string_values_scalar(void *state, char *token, JsonTokenType tokentype);
 
+static SubscriptingRef *jsonb_subscript_prepare(bool isAssignment,
+												SubscriptingRef *sbsref);
+
+static SubscriptingRef *jsonb_subscript_validate(bool isAssignment,
+												 SubscriptingRef *sbsref,
+												 ParseState *pstate);
+static Datum jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate);
+static Datum jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate);
+
 /*
  * pg_parse_json_or_ereport
  *
@@ -1447,13 +1464,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1468,9 +1481,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+static Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	Jsonb		   *res;
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	JsonbValue		tv;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1495,7 +1527,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1511,22 +1543,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1544,7 +1579,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1554,11 +1592,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1580,9 +1622,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1593,6 +1638,32 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Datum jsonbdatum, Datum *path, int path_len,
+				  Datum sourceData, Oid source_type, bool is_null)
+{
+	Jsonb			   *jb = DatumGetJsonbP(jsonbdatum);
+	JsonbValue		   *newval,
+					   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	newval = to_jsonb_worker(sourceData, source_type, is_null);
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4152,58 +4223,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4475,7 +4494,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4633,7 +4653,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4796,7 +4817,7 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 static JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4849,11 +4870,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4870,7 +4891,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4901,7 +4922,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4924,7 +4945,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4956,7 +4977,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5004,7 +5025,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5020,7 +5041,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5031,7 +5052,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5065,12 +5086,138 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
 }
 
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	return jsonb_get_element(DatumGetJsonbP(containerSource),
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 &sbstate->resnull,
+							 false);
+}
+
+
+
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	/*
+	 * the original jsonb must be non-NULL, else we punt and return the
+	 * original array.
+	 */
+	if (sbstate->resnull)
+		return containerSource;
+
+	return jsonb_set_element(containerSource,
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 sbstate->replacevalue,
+							 sbstate->refelemtype,
+							 sbstate->replacenull);
+}
+
+/*
+ * Perform preparation for the jsonb subscripting. Since there are not any
+ * particular restrictions for this kind of subscripting, we will verify that
+ * it is not a slice operation. This function produces an expression that
+ * represents the result of extracting a single container element or the new
+ * container value with the source data inserted into the right part of the
+ * container. If you have read until this point, and will submit a meaningful
+ * review of this patch series, I'll owe you a beer at the next PGConfEU.
+ */
+
+/*
+ * Handle jsonb-type subscripting logic.
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	SubscriptRoutines *sbsroutines = (SubscriptRoutines *)
+									 palloc(sizeof(SubscriptRoutines));
+
+	sbsroutines->prepare = jsonb_subscript_prepare;
+	sbsroutines->validate = jsonb_subscript_validate;
+	sbsroutines->fetch = jsonb_subscript_fetch;
+	sbsroutines->assign = jsonb_subscript_assign;
+
+	PG_RETURN_POINTER(sbsroutines);
+}
+
+SubscriptingRef *
+jsonb_subscript_prepare(bool isAssignment, SubscriptingRef *sbsref)
+{
+	if (isAssignment)
+	{
+		sbsref->refelemtype = exprType((Node *) sbsref->refassgnexpr);
+		sbsref->refassgntype = exprType((Node *) sbsref->refassgnexpr);
+	}
+	else
+		sbsref->refelemtype = JSONBOID;
+
+	return sbsref;
+}
+
+SubscriptingRef *
+jsonb_subscript_validate(bool isAssignment, SubscriptingRef *sbsref,
+						 ParseState *pstate)
+{
+	List			   *upperIndexpr = NIL;
+	ListCell		   *l;
+
+	if (sbsref->reflowerindexpr != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("jsonb subscript does not support slices"),
+				 parser_errposition(pstate, exprLocation(
+						 ((Node *) linitial(sbsref->reflowerindexpr))))));
+
+	foreach(l, sbsref->refupperindexpr)
+	{
+		Node *subexpr = (Node *) lfirst(l);
+
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(
+						((Node *) linitial(sbsref->refupperindexpr))))));
+
+		subexpr = coerce_to_target_type(pstate,
+										subexpr, exprType(subexpr),
+										TEXTOID, -1,
+										COERCION_ASSIGNMENT,
+										COERCE_IMPLICIT_CAST,
+										-1);
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript must have text type"),
+					 parser_errposition(pstate, exprLocation(subexpr))));
+
+		upperIndexpr = lappend(upperIndexpr, subexpr);
+	}
+
+	sbsref->refupperindexpr = upperIndexpr;
+
+	return sbsref;
+}
+
 /*
  * Parse information about what elements of a jsonb document we want to iterate
  * in functions iterate_json(b)_values. This information is presented in jsonb
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 8761597e12..bf0d4ef743 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10879,6 +10879,14 @@
   proargnames => '{max_data_alignment,database_block_size,blocks_per_segment,wal_block_size,bytes_per_wal_segment,max_identifier_length,max_index_columns,max_toast_chunk_size,large_object_chunk_size,float8_pass_by_value,data_page_checksum_version}',
   prosrc => 'pg_control_init' },
 
+# type subscripting support
+{ oid => '6098',
+  descr => 'Jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler',
+  prorettype => 'internal',
+  proargtypes => 'internal',
+  prosrc => 'jsonb_subscript_handler' },
+
 { oid => '6099',
   descr => 'Array subscripting logic',
   proname => 'array_subscript_handler',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 21489a02ae..fa7e1d22a5 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -456,7 +456,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubshandler => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..6e3b75d56a 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,6 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
+extern JsonbValue *to_jsonb_worker(Datum source, Oid source_type, bool is_null);
 
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..04a146a7d0 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4567,7 +4567,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4697,6 +4697,237 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+ERROR:  subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..12541e7e50 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1172,7 +1172,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1203,6 +1203,72 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--u66dlpg6gaevsofr
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v33-0004-Subscripting-documentation.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v35 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: erthalion @ 2019-02-01 10:41 UTC (permalink / raw)

Subscripting implementation for jsonb. For the sake of code reuse, some
parts of jsonb functionality were rearranged to allow use the same
functions for jsonb_set and assign subscripting operation.

Reviewed-by: Tom Lane, Arthur Zakirov
---
 src/backend/utils/adt/jsonb.c       |  27 ++-
 src/backend/utils/adt/jsonb_util.c  |  76 ++++++-
 src/backend/utils/adt/jsonfuncs.c   | 325 ++++++++++++++++++++--------
 src/include/catalog/pg_proc.dat     |   8 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   2 +
 src/test/regress/expected/jsonb.out | 233 +++++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  68 +++++-
 8 files changed, 632 insertions(+), 110 deletions(-)

diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 1e9ca046c6..f66642def3 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -1134,23 +1134,34 @@ to_jsonb(PG_FUNCTION_ARGS)
 {
 	Datum		val = PG_GETARG_DATUM(0);
 	Oid			val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
-	JsonbInState result;
-	JsonbTypeCategory tcategory;
-	Oid			outfuncoid;
+	JsonbValue *res = to_jsonb_worker(val, val_type, false);
+	PG_RETURN_POINTER(JsonbValueToJsonb(res));
+}
 
-	if (val_type == InvalidOid)
+/*
+ * Do the actual conversion to jsonb for to_jsonb function. This logic is
+ * separated because it can be useful not only in here (e.g. we use it in
+ * jsonb subscripting)
+ */
+JsonbValue *
+to_jsonb_worker(Datum source, Oid source_type, bool is_null)
+{
+	JsonbInState		result;
+	JsonbTypeCategory	tcategory;
+	Oid					outfuncoid;
+
+	if (source_type == InvalidOid)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("could not determine input data type")));
 
-	jsonb_categorize_type(val_type,
+	jsonb_categorize_type(source_type,
 						  &tcategory, &outfuncoid);
 
 	memset(&result, 0, sizeof(JsonbInState));
 
-	datum_to_jsonb(val, false, &result, tcategory, outfuncoid, false);
-
-	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
+	datum_to_jsonb(source, is_null, &result, tcategory, outfuncoid, false);
+	return result.res;
 }
 
 /*
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index d370348a1c..37508061a1 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -21,12 +21,16 @@
 #include "common/jsonapi.h"
 #include "fmgr.h"
 #include "funcapi.h"
+#include "executor/execExpr.h"
 #include "lib/stringinfo.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
+#include "parser/parse_coerce.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/hsearch.h"
+#include "utils/fmgroids.h"
 #include "utils/json.h"
 #include "utils/jsonb.h"
 #include "utils/jsonfuncs.h"
@@ -460,18 +464,22 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
+static Datum jsonb_set_element(Datum datum, Datum *path, int path_len,
+							   Datum sourceData, Oid source_type, bool is_null);
+static Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -486,6 +494,15 @@ static void transform_string_values_object_field_start(void *state, char *fname,
 static void transform_string_values_array_element_start(void *state, bool isnull);
 static void transform_string_values_scalar(void *state, char *token, JsonTokenType tokentype);
 
+static SubscriptingRef *jsonb_subscript_prepare(bool isAssignment,
+												SubscriptingRef *sbsref);
+
+static SubscriptingRef *jsonb_subscript_validate(bool isAssignment,
+												 SubscriptingRef *sbsref,
+												 ParseState *pstate);
+static Datum jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate);
+static Datum jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate);
+
 /*
  * pg_parse_json_or_ereport
  *
@@ -1447,13 +1464,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1468,9 +1481,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+static Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	Jsonb		   *res;
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	JsonbValue		tv;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1495,7 +1527,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1511,22 +1543,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1544,7 +1579,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1554,11 +1592,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1580,9 +1622,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1593,6 +1638,32 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Datum jsonbdatum, Datum *path, int path_len,
+				  Datum sourceData, Oid source_type, bool is_null)
+{
+	Jsonb			   *jb = DatumGetJsonbP(jsonbdatum);
+	JsonbValue		   *newval,
+					   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	newval = to_jsonb_worker(sourceData, source_type, is_null);
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4152,58 +4223,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4475,7 +4494,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4633,7 +4653,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4794,7 +4815,7 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 static JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4847,11 +4868,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4868,7 +4889,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4899,7 +4920,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4922,7 +4943,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4954,7 +4975,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5002,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5018,7 +5039,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5029,7 +5050,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5063,12 +5084,138 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
 }
 
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	return jsonb_get_element(DatumGetJsonbP(containerSource),
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 &sbstate->resnull,
+							 false);
+}
+
+
+
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	/*
+	 * the original jsonb must be non-NULL, else we punt and return the
+	 * original array.
+	 */
+	if (sbstate->resnull)
+		return containerSource;
+
+	return jsonb_set_element(containerSource,
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 sbstate->replacevalue,
+							 sbstate->refelemtype,
+							 sbstate->replacenull);
+}
+
+/*
+ * Perform preparation for the jsonb subscripting. Since there are not any
+ * particular restrictions for this kind of subscripting, we will verify that
+ * it is not a slice operation. This function produces an expression that
+ * represents the result of extracting a single container element or the new
+ * container value with the source data inserted into the right part of the
+ * container. If you have read until this point, and will submit a meaningful
+ * review of this patch series, I'll owe you a beer at the next PGConfEU.
+ */
+
+/*
+ * Handle jsonb-type subscripting logic.
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	SubscriptRoutines *sbsroutines = (SubscriptRoutines *)
+									 palloc(sizeof(SubscriptRoutines));
+
+	sbsroutines->prepare = jsonb_subscript_prepare;
+	sbsroutines->validate = jsonb_subscript_validate;
+	sbsroutines->fetch = jsonb_subscript_fetch;
+	sbsroutines->assign = jsonb_subscript_assign;
+
+	PG_RETURN_POINTER(sbsroutines);
+}
+
+SubscriptingRef *
+jsonb_subscript_prepare(bool isAssignment, SubscriptingRef *sbsref)
+{
+	if (isAssignment)
+	{
+		sbsref->refelemtype = exprType((Node *) sbsref->refassgnexpr);
+		sbsref->refassgntype = exprType((Node *) sbsref->refassgnexpr);
+	}
+	else
+		sbsref->refelemtype = JSONBOID;
+
+	return sbsref;
+}
+
+SubscriptingRef *
+jsonb_subscript_validate(bool isAssignment, SubscriptingRef *sbsref,
+						 ParseState *pstate)
+{
+	List			   *upperIndexpr = NIL;
+	ListCell		   *l;
+
+	if (sbsref->reflowerindexpr != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("jsonb subscript does not support slices"),
+				 parser_errposition(pstate, exprLocation(
+						 ((Node *) linitial(sbsref->reflowerindexpr))))));
+
+	foreach(l, sbsref->refupperindexpr)
+	{
+		Node *subexpr = (Node *) lfirst(l);
+
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(
+						((Node *) linitial(sbsref->refupperindexpr))))));
+
+		subexpr = coerce_to_target_type(pstate,
+										subexpr, exprType(subexpr),
+										TEXTOID, -1,
+										COERCION_ASSIGNMENT,
+										COERCE_IMPLICIT_CAST,
+										-1);
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript must have text type"),
+					 parser_errposition(pstate, exprLocation(subexpr))));
+
+		upperIndexpr = lappend(upperIndexpr, subexpr);
+	}
+
+	sbsref->refupperindexpr = upperIndexpr;
+
+	return sbsref;
+}
+
 /*
  * Parse information about what elements of a jsonb document we want to iterate
  * in functions iterate_json(b)_values. This information is presented in jsonb
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 2c6aa65bf8..abcbf97d05 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10898,6 +10898,14 @@
   proargnames => '{max_data_alignment,database_block_size,blocks_per_segment,wal_block_size,bytes_per_wal_segment,max_identifier_length,max_index_columns,max_toast_chunk_size,large_object_chunk_size,float8_pass_by_value,data_page_checksum_version}',
   prosrc => 'pg_control_init' },
 
+# type subscripting support
+{ oid => '6098',
+  descr => 'Jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler',
+  prorettype => 'internal',
+  proargtypes => 'internal',
+  prosrc => 'jsonb_subscript_handler' },
+
 { oid => '6099',
   descr => 'Array subscripting logic',
   proname => 'array_subscript_handler',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 21489a02ae..fa7e1d22a5 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -456,7 +456,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubshandler => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..6e3b75d56a 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,6 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
+extern JsonbValue *to_jsonb_worker(Datum source, Oid source_type, bool is_null);
 
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..04a146a7d0 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4567,7 +4567,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4697,6 +4697,237 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+ERROR:  subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..12541e7e50 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1172,7 +1172,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1203,6 +1203,72 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--evj76j7ekwacmcsz
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v35-0004-Subscripting-documentation.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: erthalion @ 2019-02-01 10:41 UTC (permalink / raw)

Subscripting implementation for jsonb. For the sake of code reuse, some
parts of jsonb functionality were rearranged to allow use the same
functions for jsonb_set and assign subscripting operation.

Reviewed-by: Tom Lane, Arthur Zakirov
---
 src/backend/utils/adt/jsonb.c       |  27 ++-
 src/backend/utils/adt/jsonb_util.c  |  76 ++++++-
 src/backend/utils/adt/jsonfuncs.c   | 325 ++++++++++++++++++++--------
 src/include/catalog/pg_proc.dat     |   8 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   2 +
 src/test/regress/expected/jsonb.out | 233 +++++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  68 +++++-
 8 files changed, 632 insertions(+), 110 deletions(-)

diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 1e9ca046c6..f66642def3 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -1134,23 +1134,34 @@ to_jsonb(PG_FUNCTION_ARGS)
 {
 	Datum		val = PG_GETARG_DATUM(0);
 	Oid			val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
-	JsonbInState result;
-	JsonbTypeCategory tcategory;
-	Oid			outfuncoid;
+	JsonbValue *res = to_jsonb_worker(val, val_type, false);
+	PG_RETURN_POINTER(JsonbValueToJsonb(res));
+}
 
-	if (val_type == InvalidOid)
+/*
+ * Do the actual conversion to jsonb for to_jsonb function. This logic is
+ * separated because it can be useful not only in here (e.g. we use it in
+ * jsonb subscripting)
+ */
+JsonbValue *
+to_jsonb_worker(Datum source, Oid source_type, bool is_null)
+{
+	JsonbInState		result;
+	JsonbTypeCategory	tcategory;
+	Oid					outfuncoid;
+
+	if (source_type == InvalidOid)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("could not determine input data type")));
 
-	jsonb_categorize_type(val_type,
+	jsonb_categorize_type(source_type,
 						  &tcategory, &outfuncoid);
 
 	memset(&result, 0, sizeof(JsonbInState));
 
-	datum_to_jsonb(val, false, &result, tcategory, outfuncoid, false);
-
-	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
+	datum_to_jsonb(source, is_null, &result, tcategory, outfuncoid, false);
+	return result.res;
 }
 
 /*
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 5a09d65fdc..f46a2828b3 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -21,12 +21,16 @@
 #include "common/jsonapi.h"
 #include "fmgr.h"
 #include "funcapi.h"
+#include "executor/execExpr.h"
 #include "lib/stringinfo.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
+#include "parser/parse_coerce.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/hsearch.h"
+#include "utils/fmgroids.h"
 #include "utils/json.h"
 #include "utils/jsonb.h"
 #include "utils/jsonfuncs.h"
@@ -460,18 +464,22 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
+static Datum jsonb_set_element(Datum datum, Datum *path, int path_len,
+							   Datum sourceData, Oid source_type, bool is_null);
+static Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -486,6 +494,15 @@ static void transform_string_values_object_field_start(void *state, char *fname,
 static void transform_string_values_array_element_start(void *state, bool isnull);
 static void transform_string_values_scalar(void *state, char *token, JsonTokenType tokentype);
 
+static SubscriptingRef *jsonb_subscript_prepare(bool isAssignment,
+												SubscriptingRef *sbsref);
+
+static SubscriptingRef *jsonb_subscript_validate(bool isAssignment,
+												 SubscriptingRef *sbsref,
+												 ParseState *pstate);
+static Datum jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate);
+static Datum jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate);
+
 /*
  * pg_parse_json_or_ereport
  *
@@ -1447,13 +1464,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1468,9 +1481,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+static Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	Jsonb		   *res;
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	JsonbValue		tv;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1495,7 +1527,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1511,22 +1543,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1544,7 +1579,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1554,11 +1592,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1580,9 +1622,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1593,6 +1638,32 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Datum jsonbdatum, Datum *path, int path_len,
+				  Datum sourceData, Oid source_type, bool is_null)
+{
+	Jsonb			   *jb = DatumGetJsonbP(jsonbdatum);
+	JsonbValue		   *newval,
+					   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	newval = to_jsonb_worker(sourceData, source_type, is_null);
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4152,58 +4223,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4475,7 +4494,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4633,7 +4653,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4796,7 +4817,7 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 static JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4849,11 +4870,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4870,7 +4891,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4901,7 +4922,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4924,7 +4945,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4956,7 +4977,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5004,7 +5025,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5020,7 +5041,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5031,7 +5052,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5065,12 +5086,138 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
 }
 
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	return jsonb_get_element(DatumGetJsonbP(containerSource),
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 &sbstate->resnull,
+							 false);
+}
+
+
+
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	/*
+	 * the original jsonb must be non-NULL, else we punt and return the
+	 * original array.
+	 */
+	if (sbstate->resnull)
+		return containerSource;
+
+	return jsonb_set_element(containerSource,
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 sbstate->replacevalue,
+							 sbstate->refelemtype,
+							 sbstate->replacenull);
+}
+
+/*
+ * Perform preparation for the jsonb subscripting. Since there are not any
+ * particular restrictions for this kind of subscripting, we will verify that
+ * it is not a slice operation. This function produces an expression that
+ * represents the result of extracting a single container element or the new
+ * container value with the source data inserted into the right part of the
+ * container. If you have read until this point, and will submit a meaningful
+ * review of this patch series, I'll owe you a beer at the next PGConfEU.
+ */
+
+/*
+ * Handle jsonb-type subscripting logic.
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	SubscriptRoutines *sbsroutines = (SubscriptRoutines *)
+									 palloc(sizeof(SubscriptRoutines));
+
+	sbsroutines->prepare = jsonb_subscript_prepare;
+	sbsroutines->validate = jsonb_subscript_validate;
+	sbsroutines->fetch = jsonb_subscript_fetch;
+	sbsroutines->assign = jsonb_subscript_assign;
+
+	PG_RETURN_POINTER(sbsroutines);
+}
+
+SubscriptingRef *
+jsonb_subscript_prepare(bool isAssignment, SubscriptingRef *sbsref)
+{
+	if (isAssignment)
+	{
+		sbsref->refelemtype = exprType((Node *) sbsref->refassgnexpr);
+		sbsref->refassgntype = exprType((Node *) sbsref->refassgnexpr);
+	}
+	else
+		sbsref->refelemtype = JSONBOID;
+
+	return sbsref;
+}
+
+SubscriptingRef *
+jsonb_subscript_validate(bool isAssignment, SubscriptingRef *sbsref,
+						 ParseState *pstate)
+{
+	List			   *upperIndexpr = NIL;
+	ListCell		   *l;
+
+	if (sbsref->reflowerindexpr != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("jsonb subscript does not support slices"),
+				 parser_errposition(pstate, exprLocation(
+						 ((Node *) linitial(sbsref->reflowerindexpr))))));
+
+	foreach(l, sbsref->refupperindexpr)
+	{
+		Node *subexpr = (Node *) lfirst(l);
+
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(
+						((Node *) linitial(sbsref->refupperindexpr))))));
+
+		subexpr = coerce_to_target_type(pstate,
+										subexpr, exprType(subexpr),
+										TEXTOID, -1,
+										COERCION_ASSIGNMENT,
+										COERCE_IMPLICIT_CAST,
+										-1);
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript must have text type"),
+					 parser_errposition(pstate, exprLocation(subexpr))));
+
+		upperIndexpr = lappend(upperIndexpr, subexpr);
+	}
+
+	sbsref->refupperindexpr = upperIndexpr;
+
+	return sbsref;
+}
+
 /*
  * Parse information about what elements of a jsonb document we want to iterate
  * in functions iterate_json(b)_values. This information is presented in jsonb
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 8761597e12..bf0d4ef743 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10879,6 +10879,14 @@
   proargnames => '{max_data_alignment,database_block_size,blocks_per_segment,wal_block_size,bytes_per_wal_segment,max_identifier_length,max_index_columns,max_toast_chunk_size,large_object_chunk_size,float8_pass_by_value,data_page_checksum_version}',
   prosrc => 'pg_control_init' },
 
+# type subscripting support
+{ oid => '6098',
+  descr => 'Jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler',
+  prorettype => 'internal',
+  proargtypes => 'internal',
+  prosrc => 'jsonb_subscript_handler' },
+
 { oid => '6099',
   descr => 'Array subscripting logic',
   proname => 'array_subscript_handler',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 21489a02ae..fa7e1d22a5 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -456,7 +456,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubshandler => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..6e3b75d56a 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,6 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
+extern JsonbValue *to_jsonb_worker(Datum source, Oid source_type, bool is_null);
 
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..04a146a7d0 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4567,7 +4567,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4697,6 +4697,237 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+ERROR:  subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..12541e7e50 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1172,7 +1172,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1203,6 +1203,72 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--u66dlpg6gaevsofr
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v33-0004-Subscripting-documentation.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v32 3/6] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: erthalion @ 2019-02-01 10:41 UTC (permalink / raw)

Subscripting implementation for jsonb. For the sake of code reuse, some
parts of jsonb functionality were rearranged to allow use the same
functions for jsonb_set and assign subscripting operation.

Reviewed-by: Tom Lane, Arthur Zakirov
---
 src/backend/utils/adt/jsonb.c       |  27 ++-
 src/backend/utils/adt/jsonb_util.c  |  76 ++++++-
 src/backend/utils/adt/jsonfuncs.c   | 325 ++++++++++++++++++++--------
 src/include/catalog/pg_proc.dat     |   8 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   2 +
 src/test/regress/expected/jsonb.out | 231 ++++++++++++++++++++
 src/test/regress/sql/jsonb.sql      |  66 ++++++
 8 files changed, 630 insertions(+), 108 deletions(-)

diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 1e9ca046c6..f66642def3 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -1134,23 +1134,34 @@ to_jsonb(PG_FUNCTION_ARGS)
 {
 	Datum		val = PG_GETARG_DATUM(0);
 	Oid			val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
-	JsonbInState result;
-	JsonbTypeCategory tcategory;
-	Oid			outfuncoid;
+	JsonbValue *res = to_jsonb_worker(val, val_type, false);
+	PG_RETURN_POINTER(JsonbValueToJsonb(res));
+}
 
-	if (val_type == InvalidOid)
+/*
+ * Do the actual conversion to jsonb for to_jsonb function. This logic is
+ * separated because it can be useful not only in here (e.g. we use it in
+ * jsonb subscripting)
+ */
+JsonbValue *
+to_jsonb_worker(Datum source, Oid source_type, bool is_null)
+{
+	JsonbInState		result;
+	JsonbTypeCategory	tcategory;
+	Oid					outfuncoid;
+
+	if (source_type == InvalidOid)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("could not determine input data type")));
 
-	jsonb_categorize_type(val_type,
+	jsonb_categorize_type(source_type,
 						  &tcategory, &outfuncoid);
 
 	memset(&result, 0, sizeof(JsonbInState));
 
-	datum_to_jsonb(val, false, &result, tcategory, outfuncoid, false);
-
-	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
+	datum_to_jsonb(source, is_null, &result, tcategory, outfuncoid, false);
+	return result.res;
 }
 
 /*
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 5a09d65fdc..f46a2828b3 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -21,12 +21,16 @@
 #include "common/jsonapi.h"
 #include "fmgr.h"
 #include "funcapi.h"
+#include "executor/execExpr.h"
 #include "lib/stringinfo.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
+#include "parser/parse_coerce.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/hsearch.h"
+#include "utils/fmgroids.h"
 #include "utils/json.h"
 #include "utils/jsonb.h"
 #include "utils/jsonfuncs.h"
@@ -460,18 +464,22 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
+static Datum jsonb_set_element(Datum datum, Datum *path, int path_len,
+							   Datum sourceData, Oid source_type, bool is_null);
+static Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -486,6 +494,15 @@ static void transform_string_values_object_field_start(void *state, char *fname,
 static void transform_string_values_array_element_start(void *state, bool isnull);
 static void transform_string_values_scalar(void *state, char *token, JsonTokenType tokentype);
 
+static SubscriptingRef *jsonb_subscript_prepare(bool isAssignment,
+												SubscriptingRef *sbsref);
+
+static SubscriptingRef *jsonb_subscript_validate(bool isAssignment,
+												 SubscriptingRef *sbsref,
+												 ParseState *pstate);
+static Datum jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate);
+static Datum jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate);
+
 /*
  * pg_parse_json_or_ereport
  *
@@ -1447,13 +1464,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1468,9 +1481,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+static Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	Jsonb		   *res;
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	JsonbValue		tv;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1495,7 +1527,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1511,22 +1543,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1544,7 +1579,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1554,11 +1592,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1580,9 +1622,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1593,6 +1638,32 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Datum jsonbdatum, Datum *path, int path_len,
+				  Datum sourceData, Oid source_type, bool is_null)
+{
+	Jsonb			   *jb = DatumGetJsonbP(jsonbdatum);
+	JsonbValue		   *newval,
+					   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	newval = to_jsonb_worker(sourceData, source_type, is_null);
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4152,58 +4223,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4475,7 +4494,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4633,7 +4653,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4796,7 +4817,7 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 static JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4849,11 +4870,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4870,7 +4891,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4901,7 +4922,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4924,7 +4945,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4956,7 +4977,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5004,7 +5025,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5020,7 +5041,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5031,7 +5052,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5065,12 +5086,138 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
 }
 
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	return jsonb_get_element(DatumGetJsonbP(containerSource),
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 &sbstate->resnull,
+							 false);
+}
+
+
+
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	/*
+	 * the original jsonb must be non-NULL, else we punt and return the
+	 * original array.
+	 */
+	if (sbstate->resnull)
+		return containerSource;
+
+	return jsonb_set_element(containerSource,
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 sbstate->replacevalue,
+							 sbstate->refelemtype,
+							 sbstate->replacenull);
+}
+
+/*
+ * Perform preparation for the jsonb subscripting. Since there are not any
+ * particular restrictions for this kind of subscripting, we will verify that
+ * it is not a slice operation. This function produces an expression that
+ * represents the result of extracting a single container element or the new
+ * container value with the source data inserted into the right part of the
+ * container. If you have read until this point, and will submit a meaningful
+ * review of this patch series, I'll owe you a beer at the next PGConfEU.
+ */
+
+/*
+ * Handle jsonb-type subscripting logic.
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	SubscriptRoutines *sbsroutines = (SubscriptRoutines *)
+									 palloc(sizeof(SubscriptRoutines));
+
+	sbsroutines->prepare = jsonb_subscript_prepare;
+	sbsroutines->validate = jsonb_subscript_validate;
+	sbsroutines->fetch = jsonb_subscript_fetch;
+	sbsroutines->assign = jsonb_subscript_assign;
+
+	PG_RETURN_POINTER(sbsroutines);
+}
+
+SubscriptingRef *
+jsonb_subscript_prepare(bool isAssignment, SubscriptingRef *sbsref)
+{
+	if (isAssignment)
+	{
+		sbsref->refelemtype = exprType((Node *) sbsref->refassgnexpr);
+		sbsref->refassgntype = exprType((Node *) sbsref->refassgnexpr);
+	}
+	else
+		sbsref->refelemtype = JSONBOID;
+
+	return sbsref;
+}
+
+SubscriptingRef *
+jsonb_subscript_validate(bool isAssignment, SubscriptingRef *sbsref,
+						 ParseState *pstate)
+{
+	List			   *upperIndexpr = NIL;
+	ListCell		   *l;
+
+	if (sbsref->reflowerindexpr != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("jsonb subscript does not support slices"),
+				 parser_errposition(pstate, exprLocation(
+						 ((Node *) linitial(sbsref->reflowerindexpr))))));
+
+	foreach(l, sbsref->refupperindexpr)
+	{
+		Node *subexpr = (Node *) lfirst(l);
+
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(
+						((Node *) linitial(sbsref->refupperindexpr))))));
+
+		subexpr = coerce_to_target_type(pstate,
+										subexpr, exprType(subexpr),
+										TEXTOID, -1,
+										COERCION_ASSIGNMENT,
+										COERCE_IMPLICIT_CAST,
+										-1);
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript must have text type"),
+					 parser_errposition(pstate, exprLocation(subexpr))));
+
+		upperIndexpr = lappend(upperIndexpr, subexpr);
+	}
+
+	sbsref->refupperindexpr = upperIndexpr;
+
+	return sbsref;
+}
+
 /*
  * Parse information about what elements of a jsonb document we want to iterate
  * in functions iterate_json(b)_values. This information is presented in jsonb
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 1577cb9ab8..825cb7d1c5 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10879,6 +10879,14 @@
   proargnames => '{max_data_alignment,database_block_size,blocks_per_segment,wal_block_size,bytes_per_wal_segment,max_identifier_length,max_index_columns,max_toast_chunk_size,large_object_chunk_size,float8_pass_by_value,data_page_checksum_version}',
   prosrc => 'pg_control_init' },
 
+# type subscripting support
+{ oid => '4191',
+  descr => 'Jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler',
+  prorettype => 'internal',
+  proargtypes => 'internal',
+  prosrc => 'jsonb_subscript_handler' },
+
 { oid => '4192',
   descr => 'Array subscripting logic',
   proname => 'array_subscript_handler',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 21489a02ae..fa7e1d22a5 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -456,7 +456,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubshandler => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..6e3b75d56a 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,6 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
+extern JsonbValue *to_jsonb_worker(Datum source, Oid source_type, bool is_null);
 
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..ecfaaebe06 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4697,6 +4697,237 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+ERROR:  subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..dc6f741d08 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1203,6 +1203,72 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--ques2rolqe435p6o
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v32-0004-Subscripting-documentation.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v34 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: erthalion @ 2019-02-01 10:41 UTC (permalink / raw)

Subscripting implementation for jsonb. For the sake of code reuse, some
parts of jsonb functionality were rearranged to allow use the same
functions for jsonb_set and assign subscripting operation.

Reviewed-by: Tom Lane, Arthur Zakirov
---
 src/backend/utils/adt/jsonb.c       |  27 ++-
 src/backend/utils/adt/jsonb_util.c  |  76 ++++++-
 src/backend/utils/adt/jsonfuncs.c   | 325 ++++++++++++++++++++--------
 src/include/catalog/pg_proc.dat     |   8 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   2 +
 src/test/regress/expected/jsonb.out | 233 +++++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  68 +++++-
 8 files changed, 632 insertions(+), 110 deletions(-)

diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 1e9ca046c6..f66642def3 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -1134,23 +1134,34 @@ to_jsonb(PG_FUNCTION_ARGS)
 {
 	Datum		val = PG_GETARG_DATUM(0);
 	Oid			val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
-	JsonbInState result;
-	JsonbTypeCategory tcategory;
-	Oid			outfuncoid;
+	JsonbValue *res = to_jsonb_worker(val, val_type, false);
+	PG_RETURN_POINTER(JsonbValueToJsonb(res));
+}
 
-	if (val_type == InvalidOid)
+/*
+ * Do the actual conversion to jsonb for to_jsonb function. This logic is
+ * separated because it can be useful not only in here (e.g. we use it in
+ * jsonb subscripting)
+ */
+JsonbValue *
+to_jsonb_worker(Datum source, Oid source_type, bool is_null)
+{
+	JsonbInState		result;
+	JsonbTypeCategory	tcategory;
+	Oid					outfuncoid;
+
+	if (source_type == InvalidOid)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("could not determine input data type")));
 
-	jsonb_categorize_type(val_type,
+	jsonb_categorize_type(source_type,
 						  &tcategory, &outfuncoid);
 
 	memset(&result, 0, sizeof(JsonbInState));
 
-	datum_to_jsonb(val, false, &result, tcategory, outfuncoid, false);
-
-	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
+	datum_to_jsonb(source, is_null, &result, tcategory, outfuncoid, false);
+	return result.res;
 }
 
 /*
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index d370348a1c..37508061a1 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -21,12 +21,16 @@
 #include "common/jsonapi.h"
 #include "fmgr.h"
 #include "funcapi.h"
+#include "executor/execExpr.h"
 #include "lib/stringinfo.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
+#include "parser/parse_coerce.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/hsearch.h"
+#include "utils/fmgroids.h"
 #include "utils/json.h"
 #include "utils/jsonb.h"
 #include "utils/jsonfuncs.h"
@@ -460,18 +464,22 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
+static Datum jsonb_set_element(Datum datum, Datum *path, int path_len,
+							   Datum sourceData, Oid source_type, bool is_null);
+static Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -486,6 +494,15 @@ static void transform_string_values_object_field_start(void *state, char *fname,
 static void transform_string_values_array_element_start(void *state, bool isnull);
 static void transform_string_values_scalar(void *state, char *token, JsonTokenType tokentype);
 
+static SubscriptingRef *jsonb_subscript_prepare(bool isAssignment,
+												SubscriptingRef *sbsref);
+
+static SubscriptingRef *jsonb_subscript_validate(bool isAssignment,
+												 SubscriptingRef *sbsref,
+												 ParseState *pstate);
+static Datum jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate);
+static Datum jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate);
+
 /*
  * pg_parse_json_or_ereport
  *
@@ -1447,13 +1464,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1468,9 +1481,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+static Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	Jsonb		   *res;
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	JsonbValue		tv;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1495,7 +1527,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1511,22 +1543,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1544,7 +1579,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1554,11 +1592,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1580,9 +1622,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1593,6 +1638,32 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Datum jsonbdatum, Datum *path, int path_len,
+				  Datum sourceData, Oid source_type, bool is_null)
+{
+	Jsonb			   *jb = DatumGetJsonbP(jsonbdatum);
+	JsonbValue		   *newval,
+					   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	newval = to_jsonb_worker(sourceData, source_type, is_null);
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4152,58 +4223,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4475,7 +4494,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4633,7 +4653,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4794,7 +4815,7 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 static JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4847,11 +4868,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4868,7 +4889,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4899,7 +4920,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4922,7 +4943,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4954,7 +4975,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5002,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5018,7 +5039,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5029,7 +5050,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5063,12 +5084,138 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
 }
 
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	return jsonb_get_element(DatumGetJsonbP(containerSource),
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 &sbstate->resnull,
+							 false);
+}
+
+
+
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	/*
+	 * the original jsonb must be non-NULL, else we punt and return the
+	 * original array.
+	 */
+	if (sbstate->resnull)
+		return containerSource;
+
+	return jsonb_set_element(containerSource,
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 sbstate->replacevalue,
+							 sbstate->refelemtype,
+							 sbstate->replacenull);
+}
+
+/*
+ * Perform preparation for the jsonb subscripting. Since there are not any
+ * particular restrictions for this kind of subscripting, we will verify that
+ * it is not a slice operation. This function produces an expression that
+ * represents the result of extracting a single container element or the new
+ * container value with the source data inserted into the right part of the
+ * container. If you have read until this point, and will submit a meaningful
+ * review of this patch series, I'll owe you a beer at the next PGConfEU.
+ */
+
+/*
+ * Handle jsonb-type subscripting logic.
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	SubscriptRoutines *sbsroutines = (SubscriptRoutines *)
+									 palloc(sizeof(SubscriptRoutines));
+
+	sbsroutines->prepare = jsonb_subscript_prepare;
+	sbsroutines->validate = jsonb_subscript_validate;
+	sbsroutines->fetch = jsonb_subscript_fetch;
+	sbsroutines->assign = jsonb_subscript_assign;
+
+	PG_RETURN_POINTER(sbsroutines);
+}
+
+SubscriptingRef *
+jsonb_subscript_prepare(bool isAssignment, SubscriptingRef *sbsref)
+{
+	if (isAssignment)
+	{
+		sbsref->refelemtype = exprType((Node *) sbsref->refassgnexpr);
+		sbsref->refassgntype = exprType((Node *) sbsref->refassgnexpr);
+	}
+	else
+		sbsref->refelemtype = JSONBOID;
+
+	return sbsref;
+}
+
+SubscriptingRef *
+jsonb_subscript_validate(bool isAssignment, SubscriptingRef *sbsref,
+						 ParseState *pstate)
+{
+	List			   *upperIndexpr = NIL;
+	ListCell		   *l;
+
+	if (sbsref->reflowerindexpr != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("jsonb subscript does not support slices"),
+				 parser_errposition(pstate, exprLocation(
+						 ((Node *) linitial(sbsref->reflowerindexpr))))));
+
+	foreach(l, sbsref->refupperindexpr)
+	{
+		Node *subexpr = (Node *) lfirst(l);
+
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(
+						((Node *) linitial(sbsref->refupperindexpr))))));
+
+		subexpr = coerce_to_target_type(pstate,
+										subexpr, exprType(subexpr),
+										TEXTOID, -1,
+										COERCION_ASSIGNMENT,
+										COERCE_IMPLICIT_CAST,
+										-1);
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript must have text type"),
+					 parser_errposition(pstate, exprLocation(subexpr))));
+
+		upperIndexpr = lappend(upperIndexpr, subexpr);
+	}
+
+	sbsref->refupperindexpr = upperIndexpr;
+
+	return sbsref;
+}
+
 /*
  * Parse information about what elements of a jsonb document we want to iterate
  * in functions iterate_json(b)_values. This information is presented in jsonb
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 2c6aa65bf8..abcbf97d05 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10898,6 +10898,14 @@
   proargnames => '{max_data_alignment,database_block_size,blocks_per_segment,wal_block_size,bytes_per_wal_segment,max_identifier_length,max_index_columns,max_toast_chunk_size,large_object_chunk_size,float8_pass_by_value,data_page_checksum_version}',
   prosrc => 'pg_control_init' },
 
+# type subscripting support
+{ oid => '6098',
+  descr => 'Jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler',
+  prorettype => 'internal',
+  proargtypes => 'internal',
+  prosrc => 'jsonb_subscript_handler' },
+
 { oid => '6099',
   descr => 'Array subscripting logic',
   proname => 'array_subscript_handler',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 21489a02ae..fa7e1d22a5 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -456,7 +456,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubshandler => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..6e3b75d56a 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,6 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
+extern JsonbValue *to_jsonb_worker(Datum source, Oid source_type, bool is_null);
 
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..04a146a7d0 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4567,7 +4567,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4697,6 +4697,237 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+ERROR:  subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..12541e7e50 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1172,7 +1172,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1203,6 +1203,72 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--j77abfbqdsj2lq6d
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v34-0004-Subscripting-documentation.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: erthalion @ 2019-02-01 10:41 UTC (permalink / raw)

Subscripting implementation for jsonb. For the sake of code reuse, some
parts of jsonb functionality were rearranged to allow use the same
functions for jsonb_set and assign subscripting operation.

Reviewed-by: Tom Lane, Arthur Zakirov
---
 src/backend/utils/adt/jsonb.c       |  27 ++-
 src/backend/utils/adt/jsonb_util.c  |  76 ++++++-
 src/backend/utils/adt/jsonfuncs.c   | 325 ++++++++++++++++++++--------
 src/include/catalog/pg_proc.dat     |   8 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   2 +
 src/test/regress/expected/jsonb.out | 233 +++++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  68 +++++-
 8 files changed, 632 insertions(+), 110 deletions(-)

diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 1e9ca046c6..f66642def3 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -1134,23 +1134,34 @@ to_jsonb(PG_FUNCTION_ARGS)
 {
 	Datum		val = PG_GETARG_DATUM(0);
 	Oid			val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
-	JsonbInState result;
-	JsonbTypeCategory tcategory;
-	Oid			outfuncoid;
+	JsonbValue *res = to_jsonb_worker(val, val_type, false);
+	PG_RETURN_POINTER(JsonbValueToJsonb(res));
+}
 
-	if (val_type == InvalidOid)
+/*
+ * Do the actual conversion to jsonb for to_jsonb function. This logic is
+ * separated because it can be useful not only in here (e.g. we use it in
+ * jsonb subscripting)
+ */
+JsonbValue *
+to_jsonb_worker(Datum source, Oid source_type, bool is_null)
+{
+	JsonbInState		result;
+	JsonbTypeCategory	tcategory;
+	Oid					outfuncoid;
+
+	if (source_type == InvalidOid)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("could not determine input data type")));
 
-	jsonb_categorize_type(val_type,
+	jsonb_categorize_type(source_type,
 						  &tcategory, &outfuncoid);
 
 	memset(&result, 0, sizeof(JsonbInState));
 
-	datum_to_jsonb(val, false, &result, tcategory, outfuncoid, false);
-
-	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
+	datum_to_jsonb(source, is_null, &result, tcategory, outfuncoid, false);
+	return result.res;
 }
 
 /*
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 5a09d65fdc..f46a2828b3 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -21,12 +21,16 @@
 #include "common/jsonapi.h"
 #include "fmgr.h"
 #include "funcapi.h"
+#include "executor/execExpr.h"
 #include "lib/stringinfo.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
+#include "parser/parse_coerce.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/hsearch.h"
+#include "utils/fmgroids.h"
 #include "utils/json.h"
 #include "utils/jsonb.h"
 #include "utils/jsonfuncs.h"
@@ -460,18 +464,22 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
+static Datum jsonb_set_element(Datum datum, Datum *path, int path_len,
+							   Datum sourceData, Oid source_type, bool is_null);
+static Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -486,6 +494,15 @@ static void transform_string_values_object_field_start(void *state, char *fname,
 static void transform_string_values_array_element_start(void *state, bool isnull);
 static void transform_string_values_scalar(void *state, char *token, JsonTokenType tokentype);
 
+static SubscriptingRef *jsonb_subscript_prepare(bool isAssignment,
+												SubscriptingRef *sbsref);
+
+static SubscriptingRef *jsonb_subscript_validate(bool isAssignment,
+												 SubscriptingRef *sbsref,
+												 ParseState *pstate);
+static Datum jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate);
+static Datum jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate);
+
 /*
  * pg_parse_json_or_ereport
  *
@@ -1447,13 +1464,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1468,9 +1481,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+static Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	Jsonb		   *res;
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	JsonbValue		tv;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1495,7 +1527,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1511,22 +1543,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1544,7 +1579,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1554,11 +1592,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1580,9 +1622,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1593,6 +1638,32 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Datum jsonbdatum, Datum *path, int path_len,
+				  Datum sourceData, Oid source_type, bool is_null)
+{
+	Jsonb			   *jb = DatumGetJsonbP(jsonbdatum);
+	JsonbValue		   *newval,
+					   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	newval = to_jsonb_worker(sourceData, source_type, is_null);
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4152,58 +4223,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4475,7 +4494,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4633,7 +4653,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4796,7 +4817,7 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 static JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4849,11 +4870,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4870,7 +4891,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4901,7 +4922,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4924,7 +4945,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4956,7 +4977,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5004,7 +5025,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5020,7 +5041,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5031,7 +5052,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5065,12 +5086,138 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
 }
 
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	return jsonb_get_element(DatumGetJsonbP(containerSource),
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 &sbstate->resnull,
+							 false);
+}
+
+
+
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	/*
+	 * the original jsonb must be non-NULL, else we punt and return the
+	 * original array.
+	 */
+	if (sbstate->resnull)
+		return containerSource;
+
+	return jsonb_set_element(containerSource,
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 sbstate->replacevalue,
+							 sbstate->refelemtype,
+							 sbstate->replacenull);
+}
+
+/*
+ * Perform preparation for the jsonb subscripting. Since there are not any
+ * particular restrictions for this kind of subscripting, we will verify that
+ * it is not a slice operation. This function produces an expression that
+ * represents the result of extracting a single container element or the new
+ * container value with the source data inserted into the right part of the
+ * container. If you have read until this point, and will submit a meaningful
+ * review of this patch series, I'll owe you a beer at the next PGConfEU.
+ */
+
+/*
+ * Handle jsonb-type subscripting logic.
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	SubscriptRoutines *sbsroutines = (SubscriptRoutines *)
+									 palloc(sizeof(SubscriptRoutines));
+
+	sbsroutines->prepare = jsonb_subscript_prepare;
+	sbsroutines->validate = jsonb_subscript_validate;
+	sbsroutines->fetch = jsonb_subscript_fetch;
+	sbsroutines->assign = jsonb_subscript_assign;
+
+	PG_RETURN_POINTER(sbsroutines);
+}
+
+SubscriptingRef *
+jsonb_subscript_prepare(bool isAssignment, SubscriptingRef *sbsref)
+{
+	if (isAssignment)
+	{
+		sbsref->refelemtype = exprType((Node *) sbsref->refassgnexpr);
+		sbsref->refassgntype = exprType((Node *) sbsref->refassgnexpr);
+	}
+	else
+		sbsref->refelemtype = JSONBOID;
+
+	return sbsref;
+}
+
+SubscriptingRef *
+jsonb_subscript_validate(bool isAssignment, SubscriptingRef *sbsref,
+						 ParseState *pstate)
+{
+	List			   *upperIndexpr = NIL;
+	ListCell		   *l;
+
+	if (sbsref->reflowerindexpr != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("jsonb subscript does not support slices"),
+				 parser_errposition(pstate, exprLocation(
+						 ((Node *) linitial(sbsref->reflowerindexpr))))));
+
+	foreach(l, sbsref->refupperindexpr)
+	{
+		Node *subexpr = (Node *) lfirst(l);
+
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(
+						((Node *) linitial(sbsref->refupperindexpr))))));
+
+		subexpr = coerce_to_target_type(pstate,
+										subexpr, exprType(subexpr),
+										TEXTOID, -1,
+										COERCION_ASSIGNMENT,
+										COERCE_IMPLICIT_CAST,
+										-1);
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript must have text type"),
+					 parser_errposition(pstate, exprLocation(subexpr))));
+
+		upperIndexpr = lappend(upperIndexpr, subexpr);
+	}
+
+	sbsref->refupperindexpr = upperIndexpr;
+
+	return sbsref;
+}
+
 /*
  * Parse information about what elements of a jsonb document we want to iterate
  * in functions iterate_json(b)_values. This information is presented in jsonb
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 8761597e12..bf0d4ef743 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10879,6 +10879,14 @@
   proargnames => '{max_data_alignment,database_block_size,blocks_per_segment,wal_block_size,bytes_per_wal_segment,max_identifier_length,max_index_columns,max_toast_chunk_size,large_object_chunk_size,float8_pass_by_value,data_page_checksum_version}',
   prosrc => 'pg_control_init' },
 
+# type subscripting support
+{ oid => '6098',
+  descr => 'Jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler',
+  prorettype => 'internal',
+  proargtypes => 'internal',
+  prosrc => 'jsonb_subscript_handler' },
+
 { oid => '6099',
   descr => 'Array subscripting logic',
   proname => 'array_subscript_handler',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 21489a02ae..fa7e1d22a5 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -456,7 +456,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubshandler => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..6e3b75d56a 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,6 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
+extern JsonbValue *to_jsonb_worker(Datum source, Oid source_type, bool is_null);
 
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..04a146a7d0 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4567,7 +4567,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4697,6 +4697,237 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+ERROR:  subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..12541e7e50 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1172,7 +1172,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1203,6 +1203,72 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--u66dlpg6gaevsofr
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v33-0004-Subscripting-documentation.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: erthalion @ 2019-02-01 10:41 UTC (permalink / raw)

Subscripting implementation for jsonb. For the sake of code reuse, some
parts of jsonb functionality were rearranged to allow use the same
functions for jsonb_set and assign subscripting operation.

Reviewed-by: Tom Lane, Arthur Zakirov
---
 src/backend/utils/adt/jsonb.c       |  27 ++-
 src/backend/utils/adt/jsonb_util.c  |  76 ++++++-
 src/backend/utils/adt/jsonfuncs.c   | 325 ++++++++++++++++++++--------
 src/include/catalog/pg_proc.dat     |   8 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   2 +
 src/test/regress/expected/jsonb.out | 233 +++++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  68 +++++-
 8 files changed, 632 insertions(+), 110 deletions(-)

diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 1e9ca046c6..f66642def3 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -1134,23 +1134,34 @@ to_jsonb(PG_FUNCTION_ARGS)
 {
 	Datum		val = PG_GETARG_DATUM(0);
 	Oid			val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
-	JsonbInState result;
-	JsonbTypeCategory tcategory;
-	Oid			outfuncoid;
+	JsonbValue *res = to_jsonb_worker(val, val_type, false);
+	PG_RETURN_POINTER(JsonbValueToJsonb(res));
+}
 
-	if (val_type == InvalidOid)
+/*
+ * Do the actual conversion to jsonb for to_jsonb function. This logic is
+ * separated because it can be useful not only in here (e.g. we use it in
+ * jsonb subscripting)
+ */
+JsonbValue *
+to_jsonb_worker(Datum source, Oid source_type, bool is_null)
+{
+	JsonbInState		result;
+	JsonbTypeCategory	tcategory;
+	Oid					outfuncoid;
+
+	if (source_type == InvalidOid)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("could not determine input data type")));
 
-	jsonb_categorize_type(val_type,
+	jsonb_categorize_type(source_type,
 						  &tcategory, &outfuncoid);
 
 	memset(&result, 0, sizeof(JsonbInState));
 
-	datum_to_jsonb(val, false, &result, tcategory, outfuncoid, false);
-
-	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
+	datum_to_jsonb(source, is_null, &result, tcategory, outfuncoid, false);
+	return result.res;
 }
 
 /*
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 5a09d65fdc..f46a2828b3 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -21,12 +21,16 @@
 #include "common/jsonapi.h"
 #include "fmgr.h"
 #include "funcapi.h"
+#include "executor/execExpr.h"
 #include "lib/stringinfo.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
+#include "parser/parse_coerce.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/hsearch.h"
+#include "utils/fmgroids.h"
 #include "utils/json.h"
 #include "utils/jsonb.h"
 #include "utils/jsonfuncs.h"
@@ -460,18 +464,22 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
+static Datum jsonb_set_element(Datum datum, Datum *path, int path_len,
+							   Datum sourceData, Oid source_type, bool is_null);
+static Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -486,6 +494,15 @@ static void transform_string_values_object_field_start(void *state, char *fname,
 static void transform_string_values_array_element_start(void *state, bool isnull);
 static void transform_string_values_scalar(void *state, char *token, JsonTokenType tokentype);
 
+static SubscriptingRef *jsonb_subscript_prepare(bool isAssignment,
+												SubscriptingRef *sbsref);
+
+static SubscriptingRef *jsonb_subscript_validate(bool isAssignment,
+												 SubscriptingRef *sbsref,
+												 ParseState *pstate);
+static Datum jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate);
+static Datum jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate);
+
 /*
  * pg_parse_json_or_ereport
  *
@@ -1447,13 +1464,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1468,9 +1481,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+static Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	Jsonb		   *res;
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	JsonbValue		tv;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1495,7 +1527,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1511,22 +1543,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1544,7 +1579,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1554,11 +1592,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1580,9 +1622,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1593,6 +1638,32 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Datum jsonbdatum, Datum *path, int path_len,
+				  Datum sourceData, Oid source_type, bool is_null)
+{
+	Jsonb			   *jb = DatumGetJsonbP(jsonbdatum);
+	JsonbValue		   *newval,
+					   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	newval = to_jsonb_worker(sourceData, source_type, is_null);
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4152,58 +4223,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4475,7 +4494,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4633,7 +4653,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4796,7 +4817,7 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 static JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4849,11 +4870,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4870,7 +4891,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4901,7 +4922,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4924,7 +4945,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4956,7 +4977,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5004,7 +5025,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5020,7 +5041,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5031,7 +5052,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5065,12 +5086,138 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
 }
 
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	return jsonb_get_element(DatumGetJsonbP(containerSource),
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 &sbstate->resnull,
+							 false);
+}
+
+
+
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	/*
+	 * the original jsonb must be non-NULL, else we punt and return the
+	 * original array.
+	 */
+	if (sbstate->resnull)
+		return containerSource;
+
+	return jsonb_set_element(containerSource,
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 sbstate->replacevalue,
+							 sbstate->refelemtype,
+							 sbstate->replacenull);
+}
+
+/*
+ * Perform preparation for the jsonb subscripting. Since there are not any
+ * particular restrictions for this kind of subscripting, we will verify that
+ * it is not a slice operation. This function produces an expression that
+ * represents the result of extracting a single container element or the new
+ * container value with the source data inserted into the right part of the
+ * container. If you have read until this point, and will submit a meaningful
+ * review of this patch series, I'll owe you a beer at the next PGConfEU.
+ */
+
+/*
+ * Handle jsonb-type subscripting logic.
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	SubscriptRoutines *sbsroutines = (SubscriptRoutines *)
+									 palloc(sizeof(SubscriptRoutines));
+
+	sbsroutines->prepare = jsonb_subscript_prepare;
+	sbsroutines->validate = jsonb_subscript_validate;
+	sbsroutines->fetch = jsonb_subscript_fetch;
+	sbsroutines->assign = jsonb_subscript_assign;
+
+	PG_RETURN_POINTER(sbsroutines);
+}
+
+SubscriptingRef *
+jsonb_subscript_prepare(bool isAssignment, SubscriptingRef *sbsref)
+{
+	if (isAssignment)
+	{
+		sbsref->refelemtype = exprType((Node *) sbsref->refassgnexpr);
+		sbsref->refassgntype = exprType((Node *) sbsref->refassgnexpr);
+	}
+	else
+		sbsref->refelemtype = JSONBOID;
+
+	return sbsref;
+}
+
+SubscriptingRef *
+jsonb_subscript_validate(bool isAssignment, SubscriptingRef *sbsref,
+						 ParseState *pstate)
+{
+	List			   *upperIndexpr = NIL;
+	ListCell		   *l;
+
+	if (sbsref->reflowerindexpr != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("jsonb subscript does not support slices"),
+				 parser_errposition(pstate, exprLocation(
+						 ((Node *) linitial(sbsref->reflowerindexpr))))));
+
+	foreach(l, sbsref->refupperindexpr)
+	{
+		Node *subexpr = (Node *) lfirst(l);
+
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(
+						((Node *) linitial(sbsref->refupperindexpr))))));
+
+		subexpr = coerce_to_target_type(pstate,
+										subexpr, exprType(subexpr),
+										TEXTOID, -1,
+										COERCION_ASSIGNMENT,
+										COERCE_IMPLICIT_CAST,
+										-1);
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript must have text type"),
+					 parser_errposition(pstate, exprLocation(subexpr))));
+
+		upperIndexpr = lappend(upperIndexpr, subexpr);
+	}
+
+	sbsref->refupperindexpr = upperIndexpr;
+
+	return sbsref;
+}
+
 /*
  * Parse information about what elements of a jsonb document we want to iterate
  * in functions iterate_json(b)_values. This information is presented in jsonb
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 8761597e12..bf0d4ef743 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10879,6 +10879,14 @@
   proargnames => '{max_data_alignment,database_block_size,blocks_per_segment,wal_block_size,bytes_per_wal_segment,max_identifier_length,max_index_columns,max_toast_chunk_size,large_object_chunk_size,float8_pass_by_value,data_page_checksum_version}',
   prosrc => 'pg_control_init' },
 
+# type subscripting support
+{ oid => '6098',
+  descr => 'Jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler',
+  prorettype => 'internal',
+  proargtypes => 'internal',
+  prosrc => 'jsonb_subscript_handler' },
+
 { oid => '6099',
   descr => 'Array subscripting logic',
   proname => 'array_subscript_handler',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 21489a02ae..fa7e1d22a5 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -456,7 +456,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubshandler => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..6e3b75d56a 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,6 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
+extern JsonbValue *to_jsonb_worker(Datum source, Oid source_type, bool is_null);
 
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..04a146a7d0 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4567,7 +4567,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4697,6 +4697,237 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+ERROR:  subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..12541e7e50 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1172,7 +1172,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1203,6 +1203,72 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--u66dlpg6gaevsofr
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v33-0004-Subscripting-documentation.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: erthalion @ 2019-02-01 10:41 UTC (permalink / raw)

Subscripting implementation for jsonb. For the sake of code reuse, some
parts of jsonb functionality were rearranged to allow use the same
functions for jsonb_set and assign subscripting operation.

Reviewed-by: Tom Lane, Arthur Zakirov
---
 src/backend/utils/adt/jsonb.c       |  27 ++-
 src/backend/utils/adt/jsonb_util.c  |  76 ++++++-
 src/backend/utils/adt/jsonfuncs.c   | 325 ++++++++++++++++++++--------
 src/include/catalog/pg_proc.dat     |   8 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   2 +
 src/test/regress/expected/jsonb.out | 233 +++++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  68 +++++-
 8 files changed, 632 insertions(+), 110 deletions(-)

diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 1e9ca046c6..f66642def3 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -1134,23 +1134,34 @@ to_jsonb(PG_FUNCTION_ARGS)
 {
 	Datum		val = PG_GETARG_DATUM(0);
 	Oid			val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
-	JsonbInState result;
-	JsonbTypeCategory tcategory;
-	Oid			outfuncoid;
+	JsonbValue *res = to_jsonb_worker(val, val_type, false);
+	PG_RETURN_POINTER(JsonbValueToJsonb(res));
+}
 
-	if (val_type == InvalidOid)
+/*
+ * Do the actual conversion to jsonb for to_jsonb function. This logic is
+ * separated because it can be useful not only in here (e.g. we use it in
+ * jsonb subscripting)
+ */
+JsonbValue *
+to_jsonb_worker(Datum source, Oid source_type, bool is_null)
+{
+	JsonbInState		result;
+	JsonbTypeCategory	tcategory;
+	Oid					outfuncoid;
+
+	if (source_type == InvalidOid)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("could not determine input data type")));
 
-	jsonb_categorize_type(val_type,
+	jsonb_categorize_type(source_type,
 						  &tcategory, &outfuncoid);
 
 	memset(&result, 0, sizeof(JsonbInState));
 
-	datum_to_jsonb(val, false, &result, tcategory, outfuncoid, false);
-
-	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
+	datum_to_jsonb(source, is_null, &result, tcategory, outfuncoid, false);
+	return result.res;
 }
 
 /*
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 5a09d65fdc..f46a2828b3 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -21,12 +21,16 @@
 #include "common/jsonapi.h"
 #include "fmgr.h"
 #include "funcapi.h"
+#include "executor/execExpr.h"
 #include "lib/stringinfo.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
+#include "parser/parse_coerce.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/hsearch.h"
+#include "utils/fmgroids.h"
 #include "utils/json.h"
 #include "utils/jsonb.h"
 #include "utils/jsonfuncs.h"
@@ -460,18 +464,22 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
+static Datum jsonb_set_element(Datum datum, Datum *path, int path_len,
+							   Datum sourceData, Oid source_type, bool is_null);
+static Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -486,6 +494,15 @@ static void transform_string_values_object_field_start(void *state, char *fname,
 static void transform_string_values_array_element_start(void *state, bool isnull);
 static void transform_string_values_scalar(void *state, char *token, JsonTokenType tokentype);
 
+static SubscriptingRef *jsonb_subscript_prepare(bool isAssignment,
+												SubscriptingRef *sbsref);
+
+static SubscriptingRef *jsonb_subscript_validate(bool isAssignment,
+												 SubscriptingRef *sbsref,
+												 ParseState *pstate);
+static Datum jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate);
+static Datum jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate);
+
 /*
  * pg_parse_json_or_ereport
  *
@@ -1447,13 +1464,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1468,9 +1481,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+static Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	Jsonb		   *res;
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	JsonbValue		tv;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1495,7 +1527,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1511,22 +1543,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1544,7 +1579,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1554,11 +1592,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1580,9 +1622,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1593,6 +1638,32 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Datum jsonbdatum, Datum *path, int path_len,
+				  Datum sourceData, Oid source_type, bool is_null)
+{
+	Jsonb			   *jb = DatumGetJsonbP(jsonbdatum);
+	JsonbValue		   *newval,
+					   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	newval = to_jsonb_worker(sourceData, source_type, is_null);
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4152,58 +4223,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4475,7 +4494,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4633,7 +4653,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4796,7 +4817,7 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 static JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4849,11 +4870,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4870,7 +4891,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4901,7 +4922,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4924,7 +4945,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4956,7 +4977,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5004,7 +5025,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5020,7 +5041,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5031,7 +5052,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5065,12 +5086,138 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
 }
 
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	return jsonb_get_element(DatumGetJsonbP(containerSource),
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 &sbstate->resnull,
+							 false);
+}
+
+
+
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	/*
+	 * the original jsonb must be non-NULL, else we punt and return the
+	 * original array.
+	 */
+	if (sbstate->resnull)
+		return containerSource;
+
+	return jsonb_set_element(containerSource,
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 sbstate->replacevalue,
+							 sbstate->refelemtype,
+							 sbstate->replacenull);
+}
+
+/*
+ * Perform preparation for the jsonb subscripting. Since there are not any
+ * particular restrictions for this kind of subscripting, we will verify that
+ * it is not a slice operation. This function produces an expression that
+ * represents the result of extracting a single container element or the new
+ * container value with the source data inserted into the right part of the
+ * container. If you have read until this point, and will submit a meaningful
+ * review of this patch series, I'll owe you a beer at the next PGConfEU.
+ */
+
+/*
+ * Handle jsonb-type subscripting logic.
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	SubscriptRoutines *sbsroutines = (SubscriptRoutines *)
+									 palloc(sizeof(SubscriptRoutines));
+
+	sbsroutines->prepare = jsonb_subscript_prepare;
+	sbsroutines->validate = jsonb_subscript_validate;
+	sbsroutines->fetch = jsonb_subscript_fetch;
+	sbsroutines->assign = jsonb_subscript_assign;
+
+	PG_RETURN_POINTER(sbsroutines);
+}
+
+SubscriptingRef *
+jsonb_subscript_prepare(bool isAssignment, SubscriptingRef *sbsref)
+{
+	if (isAssignment)
+	{
+		sbsref->refelemtype = exprType((Node *) sbsref->refassgnexpr);
+		sbsref->refassgntype = exprType((Node *) sbsref->refassgnexpr);
+	}
+	else
+		sbsref->refelemtype = JSONBOID;
+
+	return sbsref;
+}
+
+SubscriptingRef *
+jsonb_subscript_validate(bool isAssignment, SubscriptingRef *sbsref,
+						 ParseState *pstate)
+{
+	List			   *upperIndexpr = NIL;
+	ListCell		   *l;
+
+	if (sbsref->reflowerindexpr != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("jsonb subscript does not support slices"),
+				 parser_errposition(pstate, exprLocation(
+						 ((Node *) linitial(sbsref->reflowerindexpr))))));
+
+	foreach(l, sbsref->refupperindexpr)
+	{
+		Node *subexpr = (Node *) lfirst(l);
+
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(
+						((Node *) linitial(sbsref->refupperindexpr))))));
+
+		subexpr = coerce_to_target_type(pstate,
+										subexpr, exprType(subexpr),
+										TEXTOID, -1,
+										COERCION_ASSIGNMENT,
+										COERCE_IMPLICIT_CAST,
+										-1);
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript must have text type"),
+					 parser_errposition(pstate, exprLocation(subexpr))));
+
+		upperIndexpr = lappend(upperIndexpr, subexpr);
+	}
+
+	sbsref->refupperindexpr = upperIndexpr;
+
+	return sbsref;
+}
+
 /*
  * Parse information about what elements of a jsonb document we want to iterate
  * in functions iterate_json(b)_values. This information is presented in jsonb
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 8761597e12..bf0d4ef743 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10879,6 +10879,14 @@
   proargnames => '{max_data_alignment,database_block_size,blocks_per_segment,wal_block_size,bytes_per_wal_segment,max_identifier_length,max_index_columns,max_toast_chunk_size,large_object_chunk_size,float8_pass_by_value,data_page_checksum_version}',
   prosrc => 'pg_control_init' },
 
+# type subscripting support
+{ oid => '6098',
+  descr => 'Jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler',
+  prorettype => 'internal',
+  proargtypes => 'internal',
+  prosrc => 'jsonb_subscript_handler' },
+
 { oid => '6099',
   descr => 'Array subscripting logic',
   proname => 'array_subscript_handler',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 21489a02ae..fa7e1d22a5 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -456,7 +456,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubshandler => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..6e3b75d56a 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,6 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
+extern JsonbValue *to_jsonb_worker(Datum source, Oid source_type, bool is_null);
 
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..04a146a7d0 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4567,7 +4567,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4697,6 +4697,237 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+ERROR:  subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..12541e7e50 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1172,7 +1172,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1203,6 +1203,72 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--u66dlpg6gaevsofr
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v33-0004-Subscripting-documentation.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v32 3/6] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: erthalion @ 2019-02-01 10:41 UTC (permalink / raw)

Subscripting implementation for jsonb. For the sake of code reuse, some
parts of jsonb functionality were rearranged to allow use the same
functions for jsonb_set and assign subscripting operation.

Reviewed-by: Tom Lane, Arthur Zakirov
---
 src/backend/utils/adt/jsonb.c       |  27 ++-
 src/backend/utils/adt/jsonb_util.c  |  76 ++++++-
 src/backend/utils/adt/jsonfuncs.c   | 325 ++++++++++++++++++++--------
 src/include/catalog/pg_proc.dat     |   8 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   2 +
 src/test/regress/expected/jsonb.out | 233 +++++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  68 +++++-
 8 files changed, 632 insertions(+), 110 deletions(-)

diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 1e9ca046c6..f66642def3 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -1134,23 +1134,34 @@ to_jsonb(PG_FUNCTION_ARGS)
 {
 	Datum		val = PG_GETARG_DATUM(0);
 	Oid			val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
-	JsonbInState result;
-	JsonbTypeCategory tcategory;
-	Oid			outfuncoid;
+	JsonbValue *res = to_jsonb_worker(val, val_type, false);
+	PG_RETURN_POINTER(JsonbValueToJsonb(res));
+}
 
-	if (val_type == InvalidOid)
+/*
+ * Do the actual conversion to jsonb for to_jsonb function. This logic is
+ * separated because it can be useful not only in here (e.g. we use it in
+ * jsonb subscripting)
+ */
+JsonbValue *
+to_jsonb_worker(Datum source, Oid source_type, bool is_null)
+{
+	JsonbInState		result;
+	JsonbTypeCategory	tcategory;
+	Oid					outfuncoid;
+
+	if (source_type == InvalidOid)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("could not determine input data type")));
 
-	jsonb_categorize_type(val_type,
+	jsonb_categorize_type(source_type,
 						  &tcategory, &outfuncoid);
 
 	memset(&result, 0, sizeof(JsonbInState));
 
-	datum_to_jsonb(val, false, &result, tcategory, outfuncoid, false);
-
-	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
+	datum_to_jsonb(source, is_null, &result, tcategory, outfuncoid, false);
+	return result.res;
 }
 
 /*
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 5a09d65fdc..f46a2828b3 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -21,12 +21,16 @@
 #include "common/jsonapi.h"
 #include "fmgr.h"
 #include "funcapi.h"
+#include "executor/execExpr.h"
 #include "lib/stringinfo.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
+#include "parser/parse_coerce.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/hsearch.h"
+#include "utils/fmgroids.h"
 #include "utils/json.h"
 #include "utils/jsonb.h"
 #include "utils/jsonfuncs.h"
@@ -460,18 +464,22 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
+static Datum jsonb_set_element(Datum datum, Datum *path, int path_len,
+							   Datum sourceData, Oid source_type, bool is_null);
+static Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -486,6 +494,15 @@ static void transform_string_values_object_field_start(void *state, char *fname,
 static void transform_string_values_array_element_start(void *state, bool isnull);
 static void transform_string_values_scalar(void *state, char *token, JsonTokenType tokentype);
 
+static SubscriptingRef *jsonb_subscript_prepare(bool isAssignment,
+												SubscriptingRef *sbsref);
+
+static SubscriptingRef *jsonb_subscript_validate(bool isAssignment,
+												 SubscriptingRef *sbsref,
+												 ParseState *pstate);
+static Datum jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate);
+static Datum jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate);
+
 /*
  * pg_parse_json_or_ereport
  *
@@ -1447,13 +1464,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1468,9 +1481,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+static Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	Jsonb		   *res;
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	JsonbValue		tv;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1495,7 +1527,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1511,22 +1543,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1544,7 +1579,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1554,11 +1592,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1580,9 +1622,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1593,6 +1638,32 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Datum jsonbdatum, Datum *path, int path_len,
+				  Datum sourceData, Oid source_type, bool is_null)
+{
+	Jsonb			   *jb = DatumGetJsonbP(jsonbdatum);
+	JsonbValue		   *newval,
+					   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	newval = to_jsonb_worker(sourceData, source_type, is_null);
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4152,58 +4223,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4475,7 +4494,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4633,7 +4653,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4796,7 +4817,7 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 static JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4849,11 +4870,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4870,7 +4891,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4901,7 +4922,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4924,7 +4945,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4956,7 +4977,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5004,7 +5025,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5020,7 +5041,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5031,7 +5052,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5065,12 +5086,138 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
 }
 
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	return jsonb_get_element(DatumGetJsonbP(containerSource),
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 &sbstate->resnull,
+							 false);
+}
+
+
+
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	/*
+	 * the original jsonb must be non-NULL, else we punt and return the
+	 * original array.
+	 */
+	if (sbstate->resnull)
+		return containerSource;
+
+	return jsonb_set_element(containerSource,
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 sbstate->replacevalue,
+							 sbstate->refelemtype,
+							 sbstate->replacenull);
+}
+
+/*
+ * Perform preparation for the jsonb subscripting. Since there are not any
+ * particular restrictions for this kind of subscripting, we will verify that
+ * it is not a slice operation. This function produces an expression that
+ * represents the result of extracting a single container element or the new
+ * container value with the source data inserted into the right part of the
+ * container. If you have read until this point, and will submit a meaningful
+ * review of this patch series, I'll owe you a beer at the next PGConfEU.
+ */
+
+/*
+ * Handle jsonb-type subscripting logic.
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	SubscriptRoutines *sbsroutines = (SubscriptRoutines *)
+									 palloc(sizeof(SubscriptRoutines));
+
+	sbsroutines->prepare = jsonb_subscript_prepare;
+	sbsroutines->validate = jsonb_subscript_validate;
+	sbsroutines->fetch = jsonb_subscript_fetch;
+	sbsroutines->assign = jsonb_subscript_assign;
+
+	PG_RETURN_POINTER(sbsroutines);
+}
+
+SubscriptingRef *
+jsonb_subscript_prepare(bool isAssignment, SubscriptingRef *sbsref)
+{
+	if (isAssignment)
+	{
+		sbsref->refelemtype = exprType((Node *) sbsref->refassgnexpr);
+		sbsref->refassgntype = exprType((Node *) sbsref->refassgnexpr);
+	}
+	else
+		sbsref->refelemtype = JSONBOID;
+
+	return sbsref;
+}
+
+SubscriptingRef *
+jsonb_subscript_validate(bool isAssignment, SubscriptingRef *sbsref,
+						 ParseState *pstate)
+{
+	List			   *upperIndexpr = NIL;
+	ListCell		   *l;
+
+	if (sbsref->reflowerindexpr != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("jsonb subscript does not support slices"),
+				 parser_errposition(pstate, exprLocation(
+						 ((Node *) linitial(sbsref->reflowerindexpr))))));
+
+	foreach(l, sbsref->refupperindexpr)
+	{
+		Node *subexpr = (Node *) lfirst(l);
+
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(
+						((Node *) linitial(sbsref->refupperindexpr))))));
+
+		subexpr = coerce_to_target_type(pstate,
+										subexpr, exprType(subexpr),
+										TEXTOID, -1,
+										COERCION_ASSIGNMENT,
+										COERCE_IMPLICIT_CAST,
+										-1);
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript must have text type"),
+					 parser_errposition(pstate, exprLocation(subexpr))));
+
+		upperIndexpr = lappend(upperIndexpr, subexpr);
+	}
+
+	sbsref->refupperindexpr = upperIndexpr;
+
+	return sbsref;
+}
+
 /*
  * Parse information about what elements of a jsonb document we want to iterate
  * in functions iterate_json(b)_values. This information is presented in jsonb
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 8761597e12..bf0d4ef743 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10879,6 +10879,14 @@
   proargnames => '{max_data_alignment,database_block_size,blocks_per_segment,wal_block_size,bytes_per_wal_segment,max_identifier_length,max_index_columns,max_toast_chunk_size,large_object_chunk_size,float8_pass_by_value,data_page_checksum_version}',
   prosrc => 'pg_control_init' },
 
+# type subscripting support
+{ oid => '6098',
+  descr => 'Jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler',
+  prorettype => 'internal',
+  proargtypes => 'internal',
+  prosrc => 'jsonb_subscript_handler' },
+
 { oid => '6099',
   descr => 'Array subscripting logic',
   proname => 'array_subscript_handler',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 21489a02ae..fa7e1d22a5 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -456,7 +456,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubshandler => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..6e3b75d56a 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,6 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
+extern JsonbValue *to_jsonb_worker(Datum source, Oid source_type, bool is_null);
 
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..04a146a7d0 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4567,7 +4567,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4697,6 +4697,237 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+ERROR:  subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..12541e7e50 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1172,7 +1172,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1203,6 +1203,72 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--xuxpg5p32zizz4zy
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v32-0004-Subscripting-documentation.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: erthalion @ 2019-02-01 10:41 UTC (permalink / raw)

Subscripting implementation for jsonb. For the sake of code reuse, some
parts of jsonb functionality were rearranged to allow use the same
functions for jsonb_set and assign subscripting operation.

Reviewed-by: Tom Lane, Arthur Zakirov
---
 src/backend/utils/adt/jsonb.c       |  27 ++-
 src/backend/utils/adt/jsonb_util.c  |  76 ++++++-
 src/backend/utils/adt/jsonfuncs.c   | 325 ++++++++++++++++++++--------
 src/include/catalog/pg_proc.dat     |   8 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   2 +
 src/test/regress/expected/jsonb.out | 233 +++++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  68 +++++-
 8 files changed, 632 insertions(+), 110 deletions(-)

diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 1e9ca046c6..f66642def3 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -1134,23 +1134,34 @@ to_jsonb(PG_FUNCTION_ARGS)
 {
 	Datum		val = PG_GETARG_DATUM(0);
 	Oid			val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
-	JsonbInState result;
-	JsonbTypeCategory tcategory;
-	Oid			outfuncoid;
+	JsonbValue *res = to_jsonb_worker(val, val_type, false);
+	PG_RETURN_POINTER(JsonbValueToJsonb(res));
+}
 
-	if (val_type == InvalidOid)
+/*
+ * Do the actual conversion to jsonb for to_jsonb function. This logic is
+ * separated because it can be useful not only in here (e.g. we use it in
+ * jsonb subscripting)
+ */
+JsonbValue *
+to_jsonb_worker(Datum source, Oid source_type, bool is_null)
+{
+	JsonbInState		result;
+	JsonbTypeCategory	tcategory;
+	Oid					outfuncoid;
+
+	if (source_type == InvalidOid)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("could not determine input data type")));
 
-	jsonb_categorize_type(val_type,
+	jsonb_categorize_type(source_type,
 						  &tcategory, &outfuncoid);
 
 	memset(&result, 0, sizeof(JsonbInState));
 
-	datum_to_jsonb(val, false, &result, tcategory, outfuncoid, false);
-
-	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
+	datum_to_jsonb(source, is_null, &result, tcategory, outfuncoid, false);
+	return result.res;
 }
 
 /*
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 5a09d65fdc..f46a2828b3 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -21,12 +21,16 @@
 #include "common/jsonapi.h"
 #include "fmgr.h"
 #include "funcapi.h"
+#include "executor/execExpr.h"
 #include "lib/stringinfo.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
+#include "parser/parse_coerce.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/hsearch.h"
+#include "utils/fmgroids.h"
 #include "utils/json.h"
 #include "utils/jsonb.h"
 #include "utils/jsonfuncs.h"
@@ -460,18 +464,22 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
+static Datum jsonb_set_element(Datum datum, Datum *path, int path_len,
+							   Datum sourceData, Oid source_type, bool is_null);
+static Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -486,6 +494,15 @@ static void transform_string_values_object_field_start(void *state, char *fname,
 static void transform_string_values_array_element_start(void *state, bool isnull);
 static void transform_string_values_scalar(void *state, char *token, JsonTokenType tokentype);
 
+static SubscriptingRef *jsonb_subscript_prepare(bool isAssignment,
+												SubscriptingRef *sbsref);
+
+static SubscriptingRef *jsonb_subscript_validate(bool isAssignment,
+												 SubscriptingRef *sbsref,
+												 ParseState *pstate);
+static Datum jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate);
+static Datum jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate);
+
 /*
  * pg_parse_json_or_ereport
  *
@@ -1447,13 +1464,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1468,9 +1481,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+static Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	Jsonb		   *res;
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	JsonbValue		tv;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1495,7 +1527,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1511,22 +1543,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1544,7 +1579,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1554,11 +1592,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1580,9 +1622,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1593,6 +1638,32 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Datum jsonbdatum, Datum *path, int path_len,
+				  Datum sourceData, Oid source_type, bool is_null)
+{
+	Jsonb			   *jb = DatumGetJsonbP(jsonbdatum);
+	JsonbValue		   *newval,
+					   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	newval = to_jsonb_worker(sourceData, source_type, is_null);
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4152,58 +4223,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4475,7 +4494,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4633,7 +4653,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4796,7 +4817,7 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 static JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4849,11 +4870,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4870,7 +4891,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4901,7 +4922,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4924,7 +4945,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4956,7 +4977,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5004,7 +5025,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5020,7 +5041,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5031,7 +5052,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5065,12 +5086,138 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
 }
 
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	return jsonb_get_element(DatumGetJsonbP(containerSource),
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 &sbstate->resnull,
+							 false);
+}
+
+
+
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	/*
+	 * the original jsonb must be non-NULL, else we punt and return the
+	 * original array.
+	 */
+	if (sbstate->resnull)
+		return containerSource;
+
+	return jsonb_set_element(containerSource,
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 sbstate->replacevalue,
+							 sbstate->refelemtype,
+							 sbstate->replacenull);
+}
+
+/*
+ * Perform preparation for the jsonb subscripting. Since there are not any
+ * particular restrictions for this kind of subscripting, we will verify that
+ * it is not a slice operation. This function produces an expression that
+ * represents the result of extracting a single container element or the new
+ * container value with the source data inserted into the right part of the
+ * container. If you have read until this point, and will submit a meaningful
+ * review of this patch series, I'll owe you a beer at the next PGConfEU.
+ */
+
+/*
+ * Handle jsonb-type subscripting logic.
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	SubscriptRoutines *sbsroutines = (SubscriptRoutines *)
+									 palloc(sizeof(SubscriptRoutines));
+
+	sbsroutines->prepare = jsonb_subscript_prepare;
+	sbsroutines->validate = jsonb_subscript_validate;
+	sbsroutines->fetch = jsonb_subscript_fetch;
+	sbsroutines->assign = jsonb_subscript_assign;
+
+	PG_RETURN_POINTER(sbsroutines);
+}
+
+SubscriptingRef *
+jsonb_subscript_prepare(bool isAssignment, SubscriptingRef *sbsref)
+{
+	if (isAssignment)
+	{
+		sbsref->refelemtype = exprType((Node *) sbsref->refassgnexpr);
+		sbsref->refassgntype = exprType((Node *) sbsref->refassgnexpr);
+	}
+	else
+		sbsref->refelemtype = JSONBOID;
+
+	return sbsref;
+}
+
+SubscriptingRef *
+jsonb_subscript_validate(bool isAssignment, SubscriptingRef *sbsref,
+						 ParseState *pstate)
+{
+	List			   *upperIndexpr = NIL;
+	ListCell		   *l;
+
+	if (sbsref->reflowerindexpr != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("jsonb subscript does not support slices"),
+				 parser_errposition(pstate, exprLocation(
+						 ((Node *) linitial(sbsref->reflowerindexpr))))));
+
+	foreach(l, sbsref->refupperindexpr)
+	{
+		Node *subexpr = (Node *) lfirst(l);
+
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(
+						((Node *) linitial(sbsref->refupperindexpr))))));
+
+		subexpr = coerce_to_target_type(pstate,
+										subexpr, exprType(subexpr),
+										TEXTOID, -1,
+										COERCION_ASSIGNMENT,
+										COERCE_IMPLICIT_CAST,
+										-1);
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript must have text type"),
+					 parser_errposition(pstate, exprLocation(subexpr))));
+
+		upperIndexpr = lappend(upperIndexpr, subexpr);
+	}
+
+	sbsref->refupperindexpr = upperIndexpr;
+
+	return sbsref;
+}
+
 /*
  * Parse information about what elements of a jsonb document we want to iterate
  * in functions iterate_json(b)_values. This information is presented in jsonb
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 8761597e12..bf0d4ef743 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10879,6 +10879,14 @@
   proargnames => '{max_data_alignment,database_block_size,blocks_per_segment,wal_block_size,bytes_per_wal_segment,max_identifier_length,max_index_columns,max_toast_chunk_size,large_object_chunk_size,float8_pass_by_value,data_page_checksum_version}',
   prosrc => 'pg_control_init' },
 
+# type subscripting support
+{ oid => '6098',
+  descr => 'Jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler',
+  prorettype => 'internal',
+  proargtypes => 'internal',
+  prosrc => 'jsonb_subscript_handler' },
+
 { oid => '6099',
   descr => 'Array subscripting logic',
   proname => 'array_subscript_handler',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 21489a02ae..fa7e1d22a5 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -456,7 +456,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubshandler => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..6e3b75d56a 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,6 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
+extern JsonbValue *to_jsonb_worker(Datum source, Oid source_type, bool is_null);
 
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..04a146a7d0 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4567,7 +4567,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4697,6 +4697,237 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+ERROR:  subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..12541e7e50 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1172,7 +1172,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1203,6 +1203,72 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--u66dlpg6gaevsofr
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v33-0004-Subscripting-documentation.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: erthalion @ 2019-02-01 10:41 UTC (permalink / raw)

Subscripting implementation for jsonb. For the sake of code reuse, some
parts of jsonb functionality were rearranged to allow use the same
functions for jsonb_set and assign subscripting operation.

Reviewed-by: Tom Lane, Arthur Zakirov
---
 src/backend/utils/adt/jsonb.c       |  27 ++-
 src/backend/utils/adt/jsonb_util.c  |  76 ++++++-
 src/backend/utils/adt/jsonfuncs.c   | 325 ++++++++++++++++++++--------
 src/include/catalog/pg_proc.dat     |   8 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   2 +
 src/test/regress/expected/jsonb.out | 233 +++++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  68 +++++-
 8 files changed, 632 insertions(+), 110 deletions(-)

diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 1e9ca046c6..f66642def3 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -1134,23 +1134,34 @@ to_jsonb(PG_FUNCTION_ARGS)
 {
 	Datum		val = PG_GETARG_DATUM(0);
 	Oid			val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
-	JsonbInState result;
-	JsonbTypeCategory tcategory;
-	Oid			outfuncoid;
+	JsonbValue *res = to_jsonb_worker(val, val_type, false);
+	PG_RETURN_POINTER(JsonbValueToJsonb(res));
+}
 
-	if (val_type == InvalidOid)
+/*
+ * Do the actual conversion to jsonb for to_jsonb function. This logic is
+ * separated because it can be useful not only in here (e.g. we use it in
+ * jsonb subscripting)
+ */
+JsonbValue *
+to_jsonb_worker(Datum source, Oid source_type, bool is_null)
+{
+	JsonbInState		result;
+	JsonbTypeCategory	tcategory;
+	Oid					outfuncoid;
+
+	if (source_type == InvalidOid)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("could not determine input data type")));
 
-	jsonb_categorize_type(val_type,
+	jsonb_categorize_type(source_type,
 						  &tcategory, &outfuncoid);
 
 	memset(&result, 0, sizeof(JsonbInState));
 
-	datum_to_jsonb(val, false, &result, tcategory, outfuncoid, false);
-
-	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
+	datum_to_jsonb(source, is_null, &result, tcategory, outfuncoid, false);
+	return result.res;
 }
 
 /*
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 5a09d65fdc..f46a2828b3 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -21,12 +21,16 @@
 #include "common/jsonapi.h"
 #include "fmgr.h"
 #include "funcapi.h"
+#include "executor/execExpr.h"
 #include "lib/stringinfo.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
+#include "parser/parse_coerce.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/hsearch.h"
+#include "utils/fmgroids.h"
 #include "utils/json.h"
 #include "utils/jsonb.h"
 #include "utils/jsonfuncs.h"
@@ -460,18 +464,22 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
+static Datum jsonb_set_element(Datum datum, Datum *path, int path_len,
+							   Datum sourceData, Oid source_type, bool is_null);
+static Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -486,6 +494,15 @@ static void transform_string_values_object_field_start(void *state, char *fname,
 static void transform_string_values_array_element_start(void *state, bool isnull);
 static void transform_string_values_scalar(void *state, char *token, JsonTokenType tokentype);
 
+static SubscriptingRef *jsonb_subscript_prepare(bool isAssignment,
+												SubscriptingRef *sbsref);
+
+static SubscriptingRef *jsonb_subscript_validate(bool isAssignment,
+												 SubscriptingRef *sbsref,
+												 ParseState *pstate);
+static Datum jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate);
+static Datum jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate);
+
 /*
  * pg_parse_json_or_ereport
  *
@@ -1447,13 +1464,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1468,9 +1481,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+static Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	Jsonb		   *res;
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	JsonbValue		tv;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1495,7 +1527,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1511,22 +1543,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1544,7 +1579,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1554,11 +1592,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1580,9 +1622,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1593,6 +1638,32 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Datum jsonbdatum, Datum *path, int path_len,
+				  Datum sourceData, Oid source_type, bool is_null)
+{
+	Jsonb			   *jb = DatumGetJsonbP(jsonbdatum);
+	JsonbValue		   *newval,
+					   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	newval = to_jsonb_worker(sourceData, source_type, is_null);
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4152,58 +4223,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4475,7 +4494,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4633,7 +4653,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4796,7 +4817,7 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 static JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4849,11 +4870,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4870,7 +4891,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4901,7 +4922,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4924,7 +4945,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4956,7 +4977,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5004,7 +5025,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5020,7 +5041,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5031,7 +5052,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5065,12 +5086,138 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
 }
 
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	return jsonb_get_element(DatumGetJsonbP(containerSource),
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 &sbstate->resnull,
+							 false);
+}
+
+
+
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	/*
+	 * the original jsonb must be non-NULL, else we punt and return the
+	 * original array.
+	 */
+	if (sbstate->resnull)
+		return containerSource;
+
+	return jsonb_set_element(containerSource,
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 sbstate->replacevalue,
+							 sbstate->refelemtype,
+							 sbstate->replacenull);
+}
+
+/*
+ * Perform preparation for the jsonb subscripting. Since there are not any
+ * particular restrictions for this kind of subscripting, we will verify that
+ * it is not a slice operation. This function produces an expression that
+ * represents the result of extracting a single container element or the new
+ * container value with the source data inserted into the right part of the
+ * container. If you have read until this point, and will submit a meaningful
+ * review of this patch series, I'll owe you a beer at the next PGConfEU.
+ */
+
+/*
+ * Handle jsonb-type subscripting logic.
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	SubscriptRoutines *sbsroutines = (SubscriptRoutines *)
+									 palloc(sizeof(SubscriptRoutines));
+
+	sbsroutines->prepare = jsonb_subscript_prepare;
+	sbsroutines->validate = jsonb_subscript_validate;
+	sbsroutines->fetch = jsonb_subscript_fetch;
+	sbsroutines->assign = jsonb_subscript_assign;
+
+	PG_RETURN_POINTER(sbsroutines);
+}
+
+SubscriptingRef *
+jsonb_subscript_prepare(bool isAssignment, SubscriptingRef *sbsref)
+{
+	if (isAssignment)
+	{
+		sbsref->refelemtype = exprType((Node *) sbsref->refassgnexpr);
+		sbsref->refassgntype = exprType((Node *) sbsref->refassgnexpr);
+	}
+	else
+		sbsref->refelemtype = JSONBOID;
+
+	return sbsref;
+}
+
+SubscriptingRef *
+jsonb_subscript_validate(bool isAssignment, SubscriptingRef *sbsref,
+						 ParseState *pstate)
+{
+	List			   *upperIndexpr = NIL;
+	ListCell		   *l;
+
+	if (sbsref->reflowerindexpr != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("jsonb subscript does not support slices"),
+				 parser_errposition(pstate, exprLocation(
+						 ((Node *) linitial(sbsref->reflowerindexpr))))));
+
+	foreach(l, sbsref->refupperindexpr)
+	{
+		Node *subexpr = (Node *) lfirst(l);
+
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(
+						((Node *) linitial(sbsref->refupperindexpr))))));
+
+		subexpr = coerce_to_target_type(pstate,
+										subexpr, exprType(subexpr),
+										TEXTOID, -1,
+										COERCION_ASSIGNMENT,
+										COERCE_IMPLICIT_CAST,
+										-1);
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript must have text type"),
+					 parser_errposition(pstate, exprLocation(subexpr))));
+
+		upperIndexpr = lappend(upperIndexpr, subexpr);
+	}
+
+	sbsref->refupperindexpr = upperIndexpr;
+
+	return sbsref;
+}
+
 /*
  * Parse information about what elements of a jsonb document we want to iterate
  * in functions iterate_json(b)_values. This information is presented in jsonb
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 8761597e12..bf0d4ef743 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10879,6 +10879,14 @@
   proargnames => '{max_data_alignment,database_block_size,blocks_per_segment,wal_block_size,bytes_per_wal_segment,max_identifier_length,max_index_columns,max_toast_chunk_size,large_object_chunk_size,float8_pass_by_value,data_page_checksum_version}',
   prosrc => 'pg_control_init' },
 
+# type subscripting support
+{ oid => '6098',
+  descr => 'Jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler',
+  prorettype => 'internal',
+  proargtypes => 'internal',
+  prosrc => 'jsonb_subscript_handler' },
+
 { oid => '6099',
   descr => 'Array subscripting logic',
   proname => 'array_subscript_handler',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 21489a02ae..fa7e1d22a5 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -456,7 +456,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubshandler => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..6e3b75d56a 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,6 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
+extern JsonbValue *to_jsonb_worker(Datum source, Oid source_type, bool is_null);
 
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..04a146a7d0 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4567,7 +4567,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4697,6 +4697,237 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+ERROR:  subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..12541e7e50 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1172,7 +1172,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1203,6 +1203,72 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--u66dlpg6gaevsofr
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v33-0004-Subscripting-documentation.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: erthalion @ 2019-02-01 10:41 UTC (permalink / raw)

Subscripting implementation for jsonb. For the sake of code reuse, some
parts of jsonb functionality were rearranged to allow use the same
functions for jsonb_set and assign subscripting operation.

Reviewed-by: Tom Lane, Arthur Zakirov
---
 src/backend/utils/adt/jsonb.c       |  27 ++-
 src/backend/utils/adt/jsonb_util.c  |  76 ++++++-
 src/backend/utils/adt/jsonfuncs.c   | 325 ++++++++++++++++++++--------
 src/include/catalog/pg_proc.dat     |   8 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   2 +
 src/test/regress/expected/jsonb.out | 233 +++++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  68 +++++-
 8 files changed, 632 insertions(+), 110 deletions(-)

diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 1e9ca046c6..f66642def3 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -1134,23 +1134,34 @@ to_jsonb(PG_FUNCTION_ARGS)
 {
 	Datum		val = PG_GETARG_DATUM(0);
 	Oid			val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
-	JsonbInState result;
-	JsonbTypeCategory tcategory;
-	Oid			outfuncoid;
+	JsonbValue *res = to_jsonb_worker(val, val_type, false);
+	PG_RETURN_POINTER(JsonbValueToJsonb(res));
+}
 
-	if (val_type == InvalidOid)
+/*
+ * Do the actual conversion to jsonb for to_jsonb function. This logic is
+ * separated because it can be useful not only in here (e.g. we use it in
+ * jsonb subscripting)
+ */
+JsonbValue *
+to_jsonb_worker(Datum source, Oid source_type, bool is_null)
+{
+	JsonbInState		result;
+	JsonbTypeCategory	tcategory;
+	Oid					outfuncoid;
+
+	if (source_type == InvalidOid)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("could not determine input data type")));
 
-	jsonb_categorize_type(val_type,
+	jsonb_categorize_type(source_type,
 						  &tcategory, &outfuncoid);
 
 	memset(&result, 0, sizeof(JsonbInState));
 
-	datum_to_jsonb(val, false, &result, tcategory, outfuncoid, false);
-
-	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
+	datum_to_jsonb(source, is_null, &result, tcategory, outfuncoid, false);
+	return result.res;
 }
 
 /*
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 5a09d65fdc..f46a2828b3 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -21,12 +21,16 @@
 #include "common/jsonapi.h"
 #include "fmgr.h"
 #include "funcapi.h"
+#include "executor/execExpr.h"
 #include "lib/stringinfo.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
+#include "parser/parse_coerce.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/hsearch.h"
+#include "utils/fmgroids.h"
 #include "utils/json.h"
 #include "utils/jsonb.h"
 #include "utils/jsonfuncs.h"
@@ -460,18 +464,22 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
+static Datum jsonb_set_element(Datum datum, Datum *path, int path_len,
+							   Datum sourceData, Oid source_type, bool is_null);
+static Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -486,6 +494,15 @@ static void transform_string_values_object_field_start(void *state, char *fname,
 static void transform_string_values_array_element_start(void *state, bool isnull);
 static void transform_string_values_scalar(void *state, char *token, JsonTokenType tokentype);
 
+static SubscriptingRef *jsonb_subscript_prepare(bool isAssignment,
+												SubscriptingRef *sbsref);
+
+static SubscriptingRef *jsonb_subscript_validate(bool isAssignment,
+												 SubscriptingRef *sbsref,
+												 ParseState *pstate);
+static Datum jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate);
+static Datum jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate);
+
 /*
  * pg_parse_json_or_ereport
  *
@@ -1447,13 +1464,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1468,9 +1481,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+static Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	Jsonb		   *res;
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	JsonbValue		tv;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1495,7 +1527,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1511,22 +1543,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1544,7 +1579,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1554,11 +1592,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1580,9 +1622,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1593,6 +1638,32 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Datum jsonbdatum, Datum *path, int path_len,
+				  Datum sourceData, Oid source_type, bool is_null)
+{
+	Jsonb			   *jb = DatumGetJsonbP(jsonbdatum);
+	JsonbValue		   *newval,
+					   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	newval = to_jsonb_worker(sourceData, source_type, is_null);
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4152,58 +4223,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4475,7 +4494,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4633,7 +4653,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4796,7 +4817,7 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 static JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4849,11 +4870,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4870,7 +4891,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4901,7 +4922,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4924,7 +4945,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4956,7 +4977,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5004,7 +5025,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5020,7 +5041,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5031,7 +5052,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5065,12 +5086,138 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
 }
 
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	return jsonb_get_element(DatumGetJsonbP(containerSource),
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 &sbstate->resnull,
+							 false);
+}
+
+
+
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	/*
+	 * the original jsonb must be non-NULL, else we punt and return the
+	 * original array.
+	 */
+	if (sbstate->resnull)
+		return containerSource;
+
+	return jsonb_set_element(containerSource,
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 sbstate->replacevalue,
+							 sbstate->refelemtype,
+							 sbstate->replacenull);
+}
+
+/*
+ * Perform preparation for the jsonb subscripting. Since there are not any
+ * particular restrictions for this kind of subscripting, we will verify that
+ * it is not a slice operation. This function produces an expression that
+ * represents the result of extracting a single container element or the new
+ * container value with the source data inserted into the right part of the
+ * container. If you have read until this point, and will submit a meaningful
+ * review of this patch series, I'll owe you a beer at the next PGConfEU.
+ */
+
+/*
+ * Handle jsonb-type subscripting logic.
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	SubscriptRoutines *sbsroutines = (SubscriptRoutines *)
+									 palloc(sizeof(SubscriptRoutines));
+
+	sbsroutines->prepare = jsonb_subscript_prepare;
+	sbsroutines->validate = jsonb_subscript_validate;
+	sbsroutines->fetch = jsonb_subscript_fetch;
+	sbsroutines->assign = jsonb_subscript_assign;
+
+	PG_RETURN_POINTER(sbsroutines);
+}
+
+SubscriptingRef *
+jsonb_subscript_prepare(bool isAssignment, SubscriptingRef *sbsref)
+{
+	if (isAssignment)
+	{
+		sbsref->refelemtype = exprType((Node *) sbsref->refassgnexpr);
+		sbsref->refassgntype = exprType((Node *) sbsref->refassgnexpr);
+	}
+	else
+		sbsref->refelemtype = JSONBOID;
+
+	return sbsref;
+}
+
+SubscriptingRef *
+jsonb_subscript_validate(bool isAssignment, SubscriptingRef *sbsref,
+						 ParseState *pstate)
+{
+	List			   *upperIndexpr = NIL;
+	ListCell		   *l;
+
+	if (sbsref->reflowerindexpr != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("jsonb subscript does not support slices"),
+				 parser_errposition(pstate, exprLocation(
+						 ((Node *) linitial(sbsref->reflowerindexpr))))));
+
+	foreach(l, sbsref->refupperindexpr)
+	{
+		Node *subexpr = (Node *) lfirst(l);
+
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(
+						((Node *) linitial(sbsref->refupperindexpr))))));
+
+		subexpr = coerce_to_target_type(pstate,
+										subexpr, exprType(subexpr),
+										TEXTOID, -1,
+										COERCION_ASSIGNMENT,
+										COERCE_IMPLICIT_CAST,
+										-1);
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript must have text type"),
+					 parser_errposition(pstate, exprLocation(subexpr))));
+
+		upperIndexpr = lappend(upperIndexpr, subexpr);
+	}
+
+	sbsref->refupperindexpr = upperIndexpr;
+
+	return sbsref;
+}
+
 /*
  * Parse information about what elements of a jsonb document we want to iterate
  * in functions iterate_json(b)_values. This information is presented in jsonb
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 8761597e12..bf0d4ef743 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10879,6 +10879,14 @@
   proargnames => '{max_data_alignment,database_block_size,blocks_per_segment,wal_block_size,bytes_per_wal_segment,max_identifier_length,max_index_columns,max_toast_chunk_size,large_object_chunk_size,float8_pass_by_value,data_page_checksum_version}',
   prosrc => 'pg_control_init' },
 
+# type subscripting support
+{ oid => '6098',
+  descr => 'Jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler',
+  prorettype => 'internal',
+  proargtypes => 'internal',
+  prosrc => 'jsonb_subscript_handler' },
+
 { oid => '6099',
   descr => 'Array subscripting logic',
   proname => 'array_subscript_handler',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 21489a02ae..fa7e1d22a5 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -456,7 +456,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubshandler => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..6e3b75d56a 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,6 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
+extern JsonbValue *to_jsonb_worker(Datum source, Oid source_type, bool is_null);
 
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..04a146a7d0 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4567,7 +4567,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4697,6 +4697,237 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+ERROR:  subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..12541e7e50 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1172,7 +1172,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1203,6 +1203,72 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--u66dlpg6gaevsofr
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v33-0004-Subscripting-documentation.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: erthalion @ 2019-02-01 10:41 UTC (permalink / raw)

Subscripting implementation for jsonb. For the sake of code reuse, some
parts of jsonb functionality were rearranged to allow use the same
functions for jsonb_set and assign subscripting operation.

Reviewed-by: Tom Lane, Arthur Zakirov
---
 src/backend/utils/adt/jsonb.c       |  27 ++-
 src/backend/utils/adt/jsonb_util.c  |  76 ++++++-
 src/backend/utils/adt/jsonfuncs.c   | 325 ++++++++++++++++++++--------
 src/include/catalog/pg_proc.dat     |   8 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   2 +
 src/test/regress/expected/jsonb.out | 233 +++++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  68 +++++-
 8 files changed, 632 insertions(+), 110 deletions(-)

diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 1e9ca046c6..f66642def3 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -1134,23 +1134,34 @@ to_jsonb(PG_FUNCTION_ARGS)
 {
 	Datum		val = PG_GETARG_DATUM(0);
 	Oid			val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
-	JsonbInState result;
-	JsonbTypeCategory tcategory;
-	Oid			outfuncoid;
+	JsonbValue *res = to_jsonb_worker(val, val_type, false);
+	PG_RETURN_POINTER(JsonbValueToJsonb(res));
+}
 
-	if (val_type == InvalidOid)
+/*
+ * Do the actual conversion to jsonb for to_jsonb function. This logic is
+ * separated because it can be useful not only in here (e.g. we use it in
+ * jsonb subscripting)
+ */
+JsonbValue *
+to_jsonb_worker(Datum source, Oid source_type, bool is_null)
+{
+	JsonbInState		result;
+	JsonbTypeCategory	tcategory;
+	Oid					outfuncoid;
+
+	if (source_type == InvalidOid)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("could not determine input data type")));
 
-	jsonb_categorize_type(val_type,
+	jsonb_categorize_type(source_type,
 						  &tcategory, &outfuncoid);
 
 	memset(&result, 0, sizeof(JsonbInState));
 
-	datum_to_jsonb(val, false, &result, tcategory, outfuncoid, false);
-
-	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
+	datum_to_jsonb(source, is_null, &result, tcategory, outfuncoid, false);
+	return result.res;
 }
 
 /*
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 5a09d65fdc..f46a2828b3 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -21,12 +21,16 @@
 #include "common/jsonapi.h"
 #include "fmgr.h"
 #include "funcapi.h"
+#include "executor/execExpr.h"
 #include "lib/stringinfo.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
+#include "parser/parse_coerce.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/hsearch.h"
+#include "utils/fmgroids.h"
 #include "utils/json.h"
 #include "utils/jsonb.h"
 #include "utils/jsonfuncs.h"
@@ -460,18 +464,22 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
+static Datum jsonb_set_element(Datum datum, Datum *path, int path_len,
+							   Datum sourceData, Oid source_type, bool is_null);
+static Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -486,6 +494,15 @@ static void transform_string_values_object_field_start(void *state, char *fname,
 static void transform_string_values_array_element_start(void *state, bool isnull);
 static void transform_string_values_scalar(void *state, char *token, JsonTokenType tokentype);
 
+static SubscriptingRef *jsonb_subscript_prepare(bool isAssignment,
+												SubscriptingRef *sbsref);
+
+static SubscriptingRef *jsonb_subscript_validate(bool isAssignment,
+												 SubscriptingRef *sbsref,
+												 ParseState *pstate);
+static Datum jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate);
+static Datum jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate);
+
 /*
  * pg_parse_json_or_ereport
  *
@@ -1447,13 +1464,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1468,9 +1481,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+static Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	Jsonb		   *res;
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	JsonbValue		tv;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1495,7 +1527,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1511,22 +1543,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1544,7 +1579,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1554,11 +1592,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1580,9 +1622,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1593,6 +1638,32 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Datum jsonbdatum, Datum *path, int path_len,
+				  Datum sourceData, Oid source_type, bool is_null)
+{
+	Jsonb			   *jb = DatumGetJsonbP(jsonbdatum);
+	JsonbValue		   *newval,
+					   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	newval = to_jsonb_worker(sourceData, source_type, is_null);
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4152,58 +4223,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4475,7 +4494,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4633,7 +4653,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4796,7 +4817,7 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 static JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4849,11 +4870,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4870,7 +4891,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4901,7 +4922,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4924,7 +4945,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4956,7 +4977,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5004,7 +5025,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5020,7 +5041,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5031,7 +5052,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5065,12 +5086,138 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
 }
 
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	return jsonb_get_element(DatumGetJsonbP(containerSource),
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 &sbstate->resnull,
+							 false);
+}
+
+
+
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	/*
+	 * the original jsonb must be non-NULL, else we punt and return the
+	 * original array.
+	 */
+	if (sbstate->resnull)
+		return containerSource;
+
+	return jsonb_set_element(containerSource,
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 sbstate->replacevalue,
+							 sbstate->refelemtype,
+							 sbstate->replacenull);
+}
+
+/*
+ * Perform preparation for the jsonb subscripting. Since there are not any
+ * particular restrictions for this kind of subscripting, we will verify that
+ * it is not a slice operation. This function produces an expression that
+ * represents the result of extracting a single container element or the new
+ * container value with the source data inserted into the right part of the
+ * container. If you have read until this point, and will submit a meaningful
+ * review of this patch series, I'll owe you a beer at the next PGConfEU.
+ */
+
+/*
+ * Handle jsonb-type subscripting logic.
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	SubscriptRoutines *sbsroutines = (SubscriptRoutines *)
+									 palloc(sizeof(SubscriptRoutines));
+
+	sbsroutines->prepare = jsonb_subscript_prepare;
+	sbsroutines->validate = jsonb_subscript_validate;
+	sbsroutines->fetch = jsonb_subscript_fetch;
+	sbsroutines->assign = jsonb_subscript_assign;
+
+	PG_RETURN_POINTER(sbsroutines);
+}
+
+SubscriptingRef *
+jsonb_subscript_prepare(bool isAssignment, SubscriptingRef *sbsref)
+{
+	if (isAssignment)
+	{
+		sbsref->refelemtype = exprType((Node *) sbsref->refassgnexpr);
+		sbsref->refassgntype = exprType((Node *) sbsref->refassgnexpr);
+	}
+	else
+		sbsref->refelemtype = JSONBOID;
+
+	return sbsref;
+}
+
+SubscriptingRef *
+jsonb_subscript_validate(bool isAssignment, SubscriptingRef *sbsref,
+						 ParseState *pstate)
+{
+	List			   *upperIndexpr = NIL;
+	ListCell		   *l;
+
+	if (sbsref->reflowerindexpr != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("jsonb subscript does not support slices"),
+				 parser_errposition(pstate, exprLocation(
+						 ((Node *) linitial(sbsref->reflowerindexpr))))));
+
+	foreach(l, sbsref->refupperindexpr)
+	{
+		Node *subexpr = (Node *) lfirst(l);
+
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(
+						((Node *) linitial(sbsref->refupperindexpr))))));
+
+		subexpr = coerce_to_target_type(pstate,
+										subexpr, exprType(subexpr),
+										TEXTOID, -1,
+										COERCION_ASSIGNMENT,
+										COERCE_IMPLICIT_CAST,
+										-1);
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript must have text type"),
+					 parser_errposition(pstate, exprLocation(subexpr))));
+
+		upperIndexpr = lappend(upperIndexpr, subexpr);
+	}
+
+	sbsref->refupperindexpr = upperIndexpr;
+
+	return sbsref;
+}
+
 /*
  * Parse information about what elements of a jsonb document we want to iterate
  * in functions iterate_json(b)_values. This information is presented in jsonb
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 8761597e12..bf0d4ef743 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10879,6 +10879,14 @@
   proargnames => '{max_data_alignment,database_block_size,blocks_per_segment,wal_block_size,bytes_per_wal_segment,max_identifier_length,max_index_columns,max_toast_chunk_size,large_object_chunk_size,float8_pass_by_value,data_page_checksum_version}',
   prosrc => 'pg_control_init' },
 
+# type subscripting support
+{ oid => '6098',
+  descr => 'Jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler',
+  prorettype => 'internal',
+  proargtypes => 'internal',
+  prosrc => 'jsonb_subscript_handler' },
+
 { oid => '6099',
   descr => 'Array subscripting logic',
   proname => 'array_subscript_handler',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 21489a02ae..fa7e1d22a5 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -456,7 +456,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubshandler => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..6e3b75d56a 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,6 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
+extern JsonbValue *to_jsonb_worker(Datum source, Oid source_type, bool is_null);
 
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..04a146a7d0 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4567,7 +4567,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4697,6 +4697,237 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+ERROR:  subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..12541e7e50 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1172,7 +1172,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1203,6 +1203,72 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--u66dlpg6gaevsofr
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v33-0004-Subscripting-documentation.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: erthalion @ 2019-02-01 10:41 UTC (permalink / raw)

Subscripting implementation for jsonb. For the sake of code reuse, some
parts of jsonb functionality were rearranged to allow use the same
functions for jsonb_set and assign subscripting operation.

Reviewed-by: Tom Lane, Arthur Zakirov
---
 src/backend/utils/adt/jsonb.c       |  27 ++-
 src/backend/utils/adt/jsonb_util.c  |  76 ++++++-
 src/backend/utils/adt/jsonfuncs.c   | 325 ++++++++++++++++++++--------
 src/include/catalog/pg_proc.dat     |   8 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   2 +
 src/test/regress/expected/jsonb.out | 233 +++++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  68 +++++-
 8 files changed, 632 insertions(+), 110 deletions(-)

diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 1e9ca046c6..f66642def3 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -1134,23 +1134,34 @@ to_jsonb(PG_FUNCTION_ARGS)
 {
 	Datum		val = PG_GETARG_DATUM(0);
 	Oid			val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
-	JsonbInState result;
-	JsonbTypeCategory tcategory;
-	Oid			outfuncoid;
+	JsonbValue *res = to_jsonb_worker(val, val_type, false);
+	PG_RETURN_POINTER(JsonbValueToJsonb(res));
+}
 
-	if (val_type == InvalidOid)
+/*
+ * Do the actual conversion to jsonb for to_jsonb function. This logic is
+ * separated because it can be useful not only in here (e.g. we use it in
+ * jsonb subscripting)
+ */
+JsonbValue *
+to_jsonb_worker(Datum source, Oid source_type, bool is_null)
+{
+	JsonbInState		result;
+	JsonbTypeCategory	tcategory;
+	Oid					outfuncoid;
+
+	if (source_type == InvalidOid)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("could not determine input data type")));
 
-	jsonb_categorize_type(val_type,
+	jsonb_categorize_type(source_type,
 						  &tcategory, &outfuncoid);
 
 	memset(&result, 0, sizeof(JsonbInState));
 
-	datum_to_jsonb(val, false, &result, tcategory, outfuncoid, false);
-
-	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
+	datum_to_jsonb(source, is_null, &result, tcategory, outfuncoid, false);
+	return result.res;
 }
 
 /*
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 5a09d65fdc..f46a2828b3 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -21,12 +21,16 @@
 #include "common/jsonapi.h"
 #include "fmgr.h"
 #include "funcapi.h"
+#include "executor/execExpr.h"
 #include "lib/stringinfo.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
+#include "parser/parse_coerce.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/hsearch.h"
+#include "utils/fmgroids.h"
 #include "utils/json.h"
 #include "utils/jsonb.h"
 #include "utils/jsonfuncs.h"
@@ -460,18 +464,22 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
+static Datum jsonb_set_element(Datum datum, Datum *path, int path_len,
+							   Datum sourceData, Oid source_type, bool is_null);
+static Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -486,6 +494,15 @@ static void transform_string_values_object_field_start(void *state, char *fname,
 static void transform_string_values_array_element_start(void *state, bool isnull);
 static void transform_string_values_scalar(void *state, char *token, JsonTokenType tokentype);
 
+static SubscriptingRef *jsonb_subscript_prepare(bool isAssignment,
+												SubscriptingRef *sbsref);
+
+static SubscriptingRef *jsonb_subscript_validate(bool isAssignment,
+												 SubscriptingRef *sbsref,
+												 ParseState *pstate);
+static Datum jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate);
+static Datum jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate);
+
 /*
  * pg_parse_json_or_ereport
  *
@@ -1447,13 +1464,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1468,9 +1481,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+static Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	Jsonb		   *res;
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	JsonbValue		tv;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1495,7 +1527,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1511,22 +1543,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1544,7 +1579,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1554,11 +1592,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1580,9 +1622,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1593,6 +1638,32 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Datum jsonbdatum, Datum *path, int path_len,
+				  Datum sourceData, Oid source_type, bool is_null)
+{
+	Jsonb			   *jb = DatumGetJsonbP(jsonbdatum);
+	JsonbValue		   *newval,
+					   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	newval = to_jsonb_worker(sourceData, source_type, is_null);
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4152,58 +4223,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4475,7 +4494,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4633,7 +4653,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4796,7 +4817,7 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 static JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4849,11 +4870,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4870,7 +4891,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4901,7 +4922,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4924,7 +4945,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4956,7 +4977,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5004,7 +5025,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5020,7 +5041,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5031,7 +5052,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5065,12 +5086,138 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
 }
 
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	return jsonb_get_element(DatumGetJsonbP(containerSource),
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 &sbstate->resnull,
+							 false);
+}
+
+
+
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	/*
+	 * the original jsonb must be non-NULL, else we punt and return the
+	 * original array.
+	 */
+	if (sbstate->resnull)
+		return containerSource;
+
+	return jsonb_set_element(containerSource,
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 sbstate->replacevalue,
+							 sbstate->refelemtype,
+							 sbstate->replacenull);
+}
+
+/*
+ * Perform preparation for the jsonb subscripting. Since there are not any
+ * particular restrictions for this kind of subscripting, we will verify that
+ * it is not a slice operation. This function produces an expression that
+ * represents the result of extracting a single container element or the new
+ * container value with the source data inserted into the right part of the
+ * container. If you have read until this point, and will submit a meaningful
+ * review of this patch series, I'll owe you a beer at the next PGConfEU.
+ */
+
+/*
+ * Handle jsonb-type subscripting logic.
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	SubscriptRoutines *sbsroutines = (SubscriptRoutines *)
+									 palloc(sizeof(SubscriptRoutines));
+
+	sbsroutines->prepare = jsonb_subscript_prepare;
+	sbsroutines->validate = jsonb_subscript_validate;
+	sbsroutines->fetch = jsonb_subscript_fetch;
+	sbsroutines->assign = jsonb_subscript_assign;
+
+	PG_RETURN_POINTER(sbsroutines);
+}
+
+SubscriptingRef *
+jsonb_subscript_prepare(bool isAssignment, SubscriptingRef *sbsref)
+{
+	if (isAssignment)
+	{
+		sbsref->refelemtype = exprType((Node *) sbsref->refassgnexpr);
+		sbsref->refassgntype = exprType((Node *) sbsref->refassgnexpr);
+	}
+	else
+		sbsref->refelemtype = JSONBOID;
+
+	return sbsref;
+}
+
+SubscriptingRef *
+jsonb_subscript_validate(bool isAssignment, SubscriptingRef *sbsref,
+						 ParseState *pstate)
+{
+	List			   *upperIndexpr = NIL;
+	ListCell		   *l;
+
+	if (sbsref->reflowerindexpr != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("jsonb subscript does not support slices"),
+				 parser_errposition(pstate, exprLocation(
+						 ((Node *) linitial(sbsref->reflowerindexpr))))));
+
+	foreach(l, sbsref->refupperindexpr)
+	{
+		Node *subexpr = (Node *) lfirst(l);
+
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(
+						((Node *) linitial(sbsref->refupperindexpr))))));
+
+		subexpr = coerce_to_target_type(pstate,
+										subexpr, exprType(subexpr),
+										TEXTOID, -1,
+										COERCION_ASSIGNMENT,
+										COERCE_IMPLICIT_CAST,
+										-1);
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript must have text type"),
+					 parser_errposition(pstate, exprLocation(subexpr))));
+
+		upperIndexpr = lappend(upperIndexpr, subexpr);
+	}
+
+	sbsref->refupperindexpr = upperIndexpr;
+
+	return sbsref;
+}
+
 /*
  * Parse information about what elements of a jsonb document we want to iterate
  * in functions iterate_json(b)_values. This information is presented in jsonb
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 8761597e12..bf0d4ef743 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10879,6 +10879,14 @@
   proargnames => '{max_data_alignment,database_block_size,blocks_per_segment,wal_block_size,bytes_per_wal_segment,max_identifier_length,max_index_columns,max_toast_chunk_size,large_object_chunk_size,float8_pass_by_value,data_page_checksum_version}',
   prosrc => 'pg_control_init' },
 
+# type subscripting support
+{ oid => '6098',
+  descr => 'Jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler',
+  prorettype => 'internal',
+  proargtypes => 'internal',
+  prosrc => 'jsonb_subscript_handler' },
+
 { oid => '6099',
   descr => 'Array subscripting logic',
   proname => 'array_subscript_handler',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 21489a02ae..fa7e1d22a5 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -456,7 +456,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubshandler => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..6e3b75d56a 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,6 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
+extern JsonbValue *to_jsonb_worker(Datum source, Oid source_type, bool is_null);
 
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..04a146a7d0 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4567,7 +4567,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4697,6 +4697,237 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+ERROR:  subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..12541e7e50 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1172,7 +1172,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1203,6 +1203,72 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--u66dlpg6gaevsofr
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v33-0004-Subscripting-documentation.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v29 3/6] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: erthalion @ 2019-02-01 10:41 UTC (permalink / raw)

Subscripting implementation for jsonb. For the sake of code reuse, some
parts of jsonb functionality were rearranged to allow use the same
functions for jsonb_set and assign subscripting operation.

Reviewed-by: Tom Lane, Arthur Zakirov
---
 src/backend/utils/adt/jsonb.c       |  27 ++-
 src/backend/utils/adt/jsonb_util.c  |  76 ++++++-
 src/backend/utils/adt/jsonfuncs.c   | 325 ++++++++++++++++++++--------
 src/include/catalog/pg_proc.dat     |   8 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   2 +
 src/test/regress/expected/jsonb.out | 231 ++++++++++++++++++++
 src/test/regress/sql/jsonb.sql      |  66 ++++++
 8 files changed, 630 insertions(+), 108 deletions(-)

diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 9927d0879a..2de897342c 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -1134,23 +1134,34 @@ to_jsonb(PG_FUNCTION_ARGS)
 {
 	Datum		val = PG_GETARG_DATUM(0);
 	Oid			val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
-	JsonbInState result;
-	JsonbTypeCategory tcategory;
-	Oid			outfuncoid;
+	JsonbValue *res = to_jsonb_worker(val, val_type, false);
+	PG_RETURN_POINTER(JsonbValueToJsonb(res));
+}
 
-	if (val_type == InvalidOid)
+/*
+ * Do the actual conversion to jsonb for to_jsonb function. This logic is
+ * separated because it can be useful not only in here (e.g. we use it in
+ * jsonb subscripting)
+ */
+JsonbValue *
+to_jsonb_worker(Datum source, Oid source_type, bool is_null)
+{
+	JsonbInState		result;
+	JsonbTypeCategory	tcategory;
+	Oid					outfuncoid;
+
+	if (source_type == InvalidOid)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("could not determine input data type")));
 
-	jsonb_categorize_type(val_type,
+	jsonb_categorize_type(source_type,
 						  &tcategory, &outfuncoid);
 
 	memset(&result, 0, sizeof(JsonbInState));
 
-	datum_to_jsonb(val, false, &result, tcategory, outfuncoid, false);
-
-	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
+	datum_to_jsonb(source, is_null, &result, tcategory, outfuncoid, false);
+	return result.res;
 }
 
 /*
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 8b73903160..7be928fe2f 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -67,18 +67,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -562,6 +573,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -572,9 +607,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 1b0fb2afae..408ca7d9b2 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -20,12 +20,16 @@
 #include "catalog/pg_type.h"
 #include "fmgr.h"
 #include "funcapi.h"
+#include "executor/execExpr.h"
 #include "lib/stringinfo.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
+#include "parser/parse_coerce.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/hsearch.h"
+#include "utils/fmgroids.h"
 #include "utils/json.h"
 #include "utils/jsonapi.h"
 #include "utils/jsonb.h"
@@ -457,18 +461,22 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
+static Datum jsonb_set_element(Datum datum, Datum *path, int path_len,
+							   Datum sourceData, Oid source_type, bool is_null);
+static Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -483,6 +491,15 @@ static void transform_string_values_object_field_start(void *state, char *fname,
 static void transform_string_values_array_element_start(void *state, bool isnull);
 static void transform_string_values_scalar(void *state, char *token, JsonTokenType tokentype);
 
+static SubscriptingRef *jsonb_subscript_prepare(bool isAssignment,
+												SubscriptingRef *sbsref);
+
+static SubscriptingRef *jsonb_subscript_validate(bool isAssignment,
+												 SubscriptingRef *sbsref,
+												 ParseState *pstate);
+static Datum jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate);
+static Datum jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate);
+
 /*
  * SQL function json_object_keys
  *
@@ -1328,13 +1345,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1349,9 +1362,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, 'i',
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+static Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	Jsonb		   *res;
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	JsonbValue		tv;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1376,7 +1408,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1392,22 +1424,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1425,7 +1460,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1435,11 +1473,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1461,9 +1503,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1474,6 +1519,32 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Datum jsonbdatum, Datum *path, int path_len,
+				  Datum sourceData, Oid source_type, bool is_null)
+{
+	Jsonb			   *jb = DatumGetJsonbP(jsonbdatum);
+	JsonbValue		   *newval,
+					   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	newval = to_jsonb_worker(sourceData, source_type, is_null);
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4033,58 +4104,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4356,7 +4375,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4447,7 +4467,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4610,7 +4631,7 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 static JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4663,11 +4684,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4684,7 +4705,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4715,7 +4736,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4738,7 +4759,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4770,7 +4791,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4818,7 +4839,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -4834,7 +4855,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -4845,7 +4866,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -4879,12 +4900,138 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
 }
 
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	return jsonb_get_element(DatumGetJsonbP(containerSource),
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 &sbstate->resnull,
+							 false);
+}
+
+
+
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	/*
+	 * the original jsonb must be non-NULL, else we punt and return the
+	 * original array.
+	 */
+	if (sbstate->resnull)
+		return containerSource;
+
+	return jsonb_set_element(containerSource,
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 sbstate->replacevalue,
+							 sbstate->refelemtype,
+							 sbstate->replacenull);
+}
+
+/*
+ * Perform preparation for the jsonb subscripting. Since there are not any
+ * particular restrictions for this kind of subscripting, we will verify that
+ * it is not a slice operation. This function produces an expression that
+ * represents the result of extracting a single container element or the new
+ * container value with the source data inserted into the right part of the
+ * container. If you have read until this point, and will submit a meaningful
+ * review of this patch series, I'll owe you a beer at the next PGConfEU.
+ */
+
+/*
+ * Handle jsonb-type subscripting logic.
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	SubscriptRoutines *sbsroutines = (SubscriptRoutines *)
+									 palloc(sizeof(SubscriptRoutines));
+
+	sbsroutines->prepare = jsonb_subscript_prepare;
+	sbsroutines->validate = jsonb_subscript_validate;
+	sbsroutines->fetch = jsonb_subscript_fetch;
+	sbsroutines->assign = jsonb_subscript_assign;
+
+	PG_RETURN_POINTER(sbsroutines);
+}
+
+SubscriptingRef *
+jsonb_subscript_prepare(bool isAssignment, SubscriptingRef *sbsref)
+{
+	if (isAssignment)
+	{
+		sbsref->refelemtype = exprType((Node *) sbsref->refassgnexpr);
+		sbsref->refassgntype = exprType((Node *) sbsref->refassgnexpr);
+	}
+	else
+		sbsref->refelemtype = JSONBOID;
+
+	return sbsref;
+}
+
+SubscriptingRef *
+jsonb_subscript_validate(bool isAssignment, SubscriptingRef *sbsref,
+						 ParseState *pstate)
+{
+	List			   *upperIndexpr = NIL;
+	ListCell		   *l;
+
+	if (sbsref->reflowerindexpr != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("jsonb subscript does not support slices"),
+				 parser_errposition(pstate, exprLocation(
+						 ((Node *) linitial(sbsref->reflowerindexpr))))));
+
+	foreach(l, sbsref->refupperindexpr)
+	{
+		Node *subexpr = (Node *) lfirst(l);
+
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(
+						((Node *) linitial(sbsref->refupperindexpr))))));
+
+		subexpr = coerce_to_target_type(pstate,
+										subexpr, exprType(subexpr),
+										TEXTOID, -1,
+										COERCION_ASSIGNMENT,
+										COERCE_IMPLICIT_CAST,
+										-1);
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript must have text type"),
+					 parser_errposition(pstate, exprLocation(subexpr))));
+
+		upperIndexpr = lappend(upperIndexpr, subexpr);
+	}
+
+	sbsref->refupperindexpr = upperIndexpr;
+
+	return sbsref;
+}
+
 /*
  * Parse information about what elements of a jsonb document we want to iterate
  * in functions iterate_json(b)_values. This information is presented in jsonb
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index ab5320622e..5045afab8b 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10663,6 +10663,14 @@
   proargnames => '{max_data_alignment,database_block_size,blocks_per_segment,wal_block_size,bytes_per_wal_segment,max_identifier_length,max_index_columns,max_toast_chunk_size,large_object_chunk_size,float8_pass_by_value,data_page_checksum_version}',
   prosrc => 'pg_control_init' },
 
+# type subscripting support
+{ oid => '4191',
+  descr => 'Jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler',
+  prorettype => 'internal',
+  proargtypes => 'internal',
+  prosrc => 'jsonb_subscript_handler' },
+
 { oid => '4192',
   descr => 'Array subscripting logic',
   proname => 'array_subscript_handler',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 8b2b61ca4b..3925ecaf97 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -447,7 +447,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubshandler => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5e8179665e..6081fabb74 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,6 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
+extern JsonbValue *to_jsonb_worker(Datum source, Oid source_type, bool is_null);
 
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a2a19f8104..c7d7e30b45 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4640,6 +4640,237 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+ERROR:  subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index efd4c45185..934fa9d67a 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1183,6 +1183,72 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--adquyx6kg5n26q6j
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v29-0004-Subscripting-documentation.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v30 3/6] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: erthalion @ 2019-02-01 10:41 UTC (permalink / raw)

Subscripting implementation for jsonb. For the sake of code reuse, some
parts of jsonb functionality were rearranged to allow use the same
functions for jsonb_set and assign subscripting operation.

Reviewed-by: Tom Lane, Arthur Zakirov
---
 src/backend/utils/adt/jsonb.c       |  27 ++-
 src/backend/utils/adt/jsonb_util.c  |  76 ++++++-
 src/backend/utils/adt/jsonfuncs.c   | 325 ++++++++++++++++++++--------
 src/include/catalog/pg_proc.dat     |   8 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   2 +
 src/test/regress/expected/jsonb.out | 233 +++++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  68 +++++-
 8 files changed, 632 insertions(+), 110 deletions(-)

diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index b961d29472..ad364b4a0e 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -1134,23 +1134,34 @@ to_jsonb(PG_FUNCTION_ARGS)
 {
 	Datum		val = PG_GETARG_DATUM(0);
 	Oid			val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
-	JsonbInState result;
-	JsonbTypeCategory tcategory;
-	Oid			outfuncoid;
+	JsonbValue *res = to_jsonb_worker(val, val_type, false);
+	PG_RETURN_POINTER(JsonbValueToJsonb(res));
+}
 
-	if (val_type == InvalidOid)
+/*
+ * Do the actual conversion to jsonb for to_jsonb function. This logic is
+ * separated because it can be useful not only in here (e.g. we use it in
+ * jsonb subscripting)
+ */
+JsonbValue *
+to_jsonb_worker(Datum source, Oid source_type, bool is_null)
+{
+	JsonbInState		result;
+	JsonbTypeCategory	tcategory;
+	Oid					outfuncoid;
+
+	if (source_type == InvalidOid)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("could not determine input data type")));
 
-	jsonb_categorize_type(val_type,
+	jsonb_categorize_type(source_type,
 						  &tcategory, &outfuncoid);
 
 	memset(&result, 0, sizeof(JsonbInState));
 
-	datum_to_jsonb(val, false, &result, tcategory, outfuncoid, false);
-
-	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
+	datum_to_jsonb(source, is_null, &result, tcategory, outfuncoid, false);
+	return result.res;
 }
 
 /*
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 04b70c805b..adcf16acf1 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index f92861d8d2..538740aec9 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -21,12 +21,16 @@
 #include "common/jsonapi.h"
 #include "fmgr.h"
 #include "funcapi.h"
+#include "executor/execExpr.h"
 #include "lib/stringinfo.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
+#include "parser/parse_coerce.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/hsearch.h"
+#include "utils/fmgroids.h"
 #include "utils/json.h"
 #include "utils/jsonb.h"
 #include "utils/jsonfuncs.h"
@@ -460,18 +464,22 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
+static Datum jsonb_set_element(Datum datum, Datum *path, int path_len,
+							   Datum sourceData, Oid source_type, bool is_null);
+static Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -486,6 +494,15 @@ static void transform_string_values_object_field_start(void *state, char *fname,
 static void transform_string_values_array_element_start(void *state, bool isnull);
 static void transform_string_values_scalar(void *state, char *token, JsonTokenType tokentype);
 
+static SubscriptingRef *jsonb_subscript_prepare(bool isAssignment,
+												SubscriptingRef *sbsref);
+
+static SubscriptingRef *jsonb_subscript_validate(bool isAssignment,
+												 SubscriptingRef *sbsref,
+												 ParseState *pstate);
+static Datum jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate);
+static Datum jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate);
+
 /*
  * pg_parse_json_or_ereport
  *
@@ -1461,13 +1478,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1482,9 +1495,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+static Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	Jsonb		   *res;
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	JsonbValue		tv;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1509,7 +1541,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1525,22 +1557,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1558,7 +1593,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1568,11 +1606,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1594,9 +1636,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1607,6 +1652,32 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Datum jsonbdatum, Datum *path, int path_len,
+				  Datum sourceData, Oid source_type, bool is_null)
+{
+	Jsonb			   *jb = DatumGetJsonbP(jsonbdatum);
+	JsonbValue		   *newval,
+					   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	newval = to_jsonb_worker(sourceData, source_type, is_null);
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4166,58 +4237,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4489,7 +4508,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4646,7 +4666,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4809,7 +4830,7 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 static JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4862,11 +4883,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4883,7 +4904,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4914,7 +4935,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4937,7 +4958,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4969,7 +4990,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5017,7 +5038,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5033,7 +5054,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5044,7 +5065,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5078,12 +5099,138 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
 }
 
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	return jsonb_get_element(DatumGetJsonbP(containerSource),
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 &sbstate->resnull,
+							 false);
+}
+
+
+
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	/*
+	 * the original jsonb must be non-NULL, else we punt and return the
+	 * original array.
+	 */
+	if (sbstate->resnull)
+		return containerSource;
+
+	return jsonb_set_element(containerSource,
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 sbstate->replacevalue,
+							 sbstate->refelemtype,
+							 sbstate->replacenull);
+}
+
+/*
+ * Perform preparation for the jsonb subscripting. Since there are not any
+ * particular restrictions for this kind of subscripting, we will verify that
+ * it is not a slice operation. This function produces an expression that
+ * represents the result of extracting a single container element or the new
+ * container value with the source data inserted into the right part of the
+ * container. If you have read until this point, and will submit a meaningful
+ * review of this patch series, I'll owe you a beer at the next PGConfEU.
+ */
+
+/*
+ * Handle jsonb-type subscripting logic.
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	SubscriptRoutines *sbsroutines = (SubscriptRoutines *)
+									 palloc(sizeof(SubscriptRoutines));
+
+	sbsroutines->prepare = jsonb_subscript_prepare;
+	sbsroutines->validate = jsonb_subscript_validate;
+	sbsroutines->fetch = jsonb_subscript_fetch;
+	sbsroutines->assign = jsonb_subscript_assign;
+
+	PG_RETURN_POINTER(sbsroutines);
+}
+
+SubscriptingRef *
+jsonb_subscript_prepare(bool isAssignment, SubscriptingRef *sbsref)
+{
+	if (isAssignment)
+	{
+		sbsref->refelemtype = exprType((Node *) sbsref->refassgnexpr);
+		sbsref->refassgntype = exprType((Node *) sbsref->refassgnexpr);
+	}
+	else
+		sbsref->refelemtype = JSONBOID;
+
+	return sbsref;
+}
+
+SubscriptingRef *
+jsonb_subscript_validate(bool isAssignment, SubscriptingRef *sbsref,
+						 ParseState *pstate)
+{
+	List			   *upperIndexpr = NIL;
+	ListCell		   *l;
+
+	if (sbsref->reflowerindexpr != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("jsonb subscript does not support slices"),
+				 parser_errposition(pstate, exprLocation(
+						 ((Node *) linitial(sbsref->reflowerindexpr))))));
+
+	foreach(l, sbsref->refupperindexpr)
+	{
+		Node *subexpr = (Node *) lfirst(l);
+
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(
+						((Node *) linitial(sbsref->refupperindexpr))))));
+
+		subexpr = coerce_to_target_type(pstate,
+										subexpr, exprType(subexpr),
+										TEXTOID, -1,
+										COERCION_ASSIGNMENT,
+										COERCE_IMPLICIT_CAST,
+										-1);
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript must have text type"),
+					 parser_errposition(pstate, exprLocation(subexpr))));
+
+		upperIndexpr = lappend(upperIndexpr, subexpr);
+	}
+
+	sbsref->refupperindexpr = upperIndexpr;
+
+	return sbsref;
+}
+
 /*
  * Parse information about what elements of a jsonb document we want to iterate
  * in functions iterate_json(b)_values. This information is presented in jsonb
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 6de2dd29f1..36637afefb 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10707,6 +10707,14 @@
   proargnames => '{max_data_alignment,database_block_size,blocks_per_segment,wal_block_size,bytes_per_wal_segment,max_identifier_length,max_index_columns,max_toast_chunk_size,large_object_chunk_size,float8_pass_by_value,data_page_checksum_version}',
   prosrc => 'pg_control_init' },
 
+# type subscripting support
+{ oid => '4191',
+  descr => 'Jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler',
+  prorettype => 'internal',
+  proargtypes => 'internal',
+  prosrc => 'jsonb_subscript_handler' },
+
 { oid => '4192',
   descr => 'Array subscripting logic',
   proname => 'array_subscript_handler',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index f868a6d52e..64c0c6d519 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -447,7 +447,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubshandler => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..6e3b75d56a 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,6 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
+extern JsonbValue *to_jsonb_worker(Datum source, Oid source_type, bool is_null);
 
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..04a146a7d0 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4567,7 +4567,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4697,6 +4697,237 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+ERROR:  subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..12541e7e50 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1172,7 +1172,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1203,6 +1203,72 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--g5st7yssq7xavhfb
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v30-0004-Subscripting-documentation.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: erthalion @ 2019-02-01 10:41 UTC (permalink / raw)

Subscripting implementation for jsonb. For the sake of code reuse, some
parts of jsonb functionality were rearranged to allow use the same
functions for jsonb_set and assign subscripting operation.

Reviewed-by: Tom Lane, Arthur Zakirov
---
 src/backend/utils/adt/jsonb.c       |  27 ++-
 src/backend/utils/adt/jsonb_util.c  |  76 ++++++-
 src/backend/utils/adt/jsonfuncs.c   | 325 ++++++++++++++++++++--------
 src/include/catalog/pg_proc.dat     |   8 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   2 +
 src/test/regress/expected/jsonb.out | 233 +++++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  68 +++++-
 8 files changed, 632 insertions(+), 110 deletions(-)

diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 1e9ca046c6..f66642def3 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -1134,23 +1134,34 @@ to_jsonb(PG_FUNCTION_ARGS)
 {
 	Datum		val = PG_GETARG_DATUM(0);
 	Oid			val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
-	JsonbInState result;
-	JsonbTypeCategory tcategory;
-	Oid			outfuncoid;
+	JsonbValue *res = to_jsonb_worker(val, val_type, false);
+	PG_RETURN_POINTER(JsonbValueToJsonb(res));
+}
 
-	if (val_type == InvalidOid)
+/*
+ * Do the actual conversion to jsonb for to_jsonb function. This logic is
+ * separated because it can be useful not only in here (e.g. we use it in
+ * jsonb subscripting)
+ */
+JsonbValue *
+to_jsonb_worker(Datum source, Oid source_type, bool is_null)
+{
+	JsonbInState		result;
+	JsonbTypeCategory	tcategory;
+	Oid					outfuncoid;
+
+	if (source_type == InvalidOid)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("could not determine input data type")));
 
-	jsonb_categorize_type(val_type,
+	jsonb_categorize_type(source_type,
 						  &tcategory, &outfuncoid);
 
 	memset(&result, 0, sizeof(JsonbInState));
 
-	datum_to_jsonb(val, false, &result, tcategory, outfuncoid, false);
-
-	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
+	datum_to_jsonb(source, is_null, &result, tcategory, outfuncoid, false);
+	return result.res;
 }
 
 /*
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 5a09d65fdc..f46a2828b3 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -21,12 +21,16 @@
 #include "common/jsonapi.h"
 #include "fmgr.h"
 #include "funcapi.h"
+#include "executor/execExpr.h"
 #include "lib/stringinfo.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
+#include "parser/parse_coerce.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/hsearch.h"
+#include "utils/fmgroids.h"
 #include "utils/json.h"
 #include "utils/jsonb.h"
 #include "utils/jsonfuncs.h"
@@ -460,18 +464,22 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
+static Datum jsonb_set_element(Datum datum, Datum *path, int path_len,
+							   Datum sourceData, Oid source_type, bool is_null);
+static Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -486,6 +494,15 @@ static void transform_string_values_object_field_start(void *state, char *fname,
 static void transform_string_values_array_element_start(void *state, bool isnull);
 static void transform_string_values_scalar(void *state, char *token, JsonTokenType tokentype);
 
+static SubscriptingRef *jsonb_subscript_prepare(bool isAssignment,
+												SubscriptingRef *sbsref);
+
+static SubscriptingRef *jsonb_subscript_validate(bool isAssignment,
+												 SubscriptingRef *sbsref,
+												 ParseState *pstate);
+static Datum jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate);
+static Datum jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate);
+
 /*
  * pg_parse_json_or_ereport
  *
@@ -1447,13 +1464,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1468,9 +1481,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+static Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	Jsonb		   *res;
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	JsonbValue		tv;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1495,7 +1527,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1511,22 +1543,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1544,7 +1579,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1554,11 +1592,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1580,9 +1622,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1593,6 +1638,32 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Datum jsonbdatum, Datum *path, int path_len,
+				  Datum sourceData, Oid source_type, bool is_null)
+{
+	Jsonb			   *jb = DatumGetJsonbP(jsonbdatum);
+	JsonbValue		   *newval,
+					   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	newval = to_jsonb_worker(sourceData, source_type, is_null);
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4152,58 +4223,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4475,7 +4494,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4633,7 +4653,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4796,7 +4817,7 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 static JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4849,11 +4870,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4870,7 +4891,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4901,7 +4922,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4924,7 +4945,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4956,7 +4977,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5004,7 +5025,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5020,7 +5041,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5031,7 +5052,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5065,12 +5086,138 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
 }
 
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	return jsonb_get_element(DatumGetJsonbP(containerSource),
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 &sbstate->resnull,
+							 false);
+}
+
+
+
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	/*
+	 * the original jsonb must be non-NULL, else we punt and return the
+	 * original array.
+	 */
+	if (sbstate->resnull)
+		return containerSource;
+
+	return jsonb_set_element(containerSource,
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 sbstate->replacevalue,
+							 sbstate->refelemtype,
+							 sbstate->replacenull);
+}
+
+/*
+ * Perform preparation for the jsonb subscripting. Since there are not any
+ * particular restrictions for this kind of subscripting, we will verify that
+ * it is not a slice operation. This function produces an expression that
+ * represents the result of extracting a single container element or the new
+ * container value with the source data inserted into the right part of the
+ * container. If you have read until this point, and will submit a meaningful
+ * review of this patch series, I'll owe you a beer at the next PGConfEU.
+ */
+
+/*
+ * Handle jsonb-type subscripting logic.
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	SubscriptRoutines *sbsroutines = (SubscriptRoutines *)
+									 palloc(sizeof(SubscriptRoutines));
+
+	sbsroutines->prepare = jsonb_subscript_prepare;
+	sbsroutines->validate = jsonb_subscript_validate;
+	sbsroutines->fetch = jsonb_subscript_fetch;
+	sbsroutines->assign = jsonb_subscript_assign;
+
+	PG_RETURN_POINTER(sbsroutines);
+}
+
+SubscriptingRef *
+jsonb_subscript_prepare(bool isAssignment, SubscriptingRef *sbsref)
+{
+	if (isAssignment)
+	{
+		sbsref->refelemtype = exprType((Node *) sbsref->refassgnexpr);
+		sbsref->refassgntype = exprType((Node *) sbsref->refassgnexpr);
+	}
+	else
+		sbsref->refelemtype = JSONBOID;
+
+	return sbsref;
+}
+
+SubscriptingRef *
+jsonb_subscript_validate(bool isAssignment, SubscriptingRef *sbsref,
+						 ParseState *pstate)
+{
+	List			   *upperIndexpr = NIL;
+	ListCell		   *l;
+
+	if (sbsref->reflowerindexpr != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("jsonb subscript does not support slices"),
+				 parser_errposition(pstate, exprLocation(
+						 ((Node *) linitial(sbsref->reflowerindexpr))))));
+
+	foreach(l, sbsref->refupperindexpr)
+	{
+		Node *subexpr = (Node *) lfirst(l);
+
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(
+						((Node *) linitial(sbsref->refupperindexpr))))));
+
+		subexpr = coerce_to_target_type(pstate,
+										subexpr, exprType(subexpr),
+										TEXTOID, -1,
+										COERCION_ASSIGNMENT,
+										COERCE_IMPLICIT_CAST,
+										-1);
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript must have text type"),
+					 parser_errposition(pstate, exprLocation(subexpr))));
+
+		upperIndexpr = lappend(upperIndexpr, subexpr);
+	}
+
+	sbsref->refupperindexpr = upperIndexpr;
+
+	return sbsref;
+}
+
 /*
  * Parse information about what elements of a jsonb document we want to iterate
  * in functions iterate_json(b)_values. This information is presented in jsonb
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 8761597e12..bf0d4ef743 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10879,6 +10879,14 @@
   proargnames => '{max_data_alignment,database_block_size,blocks_per_segment,wal_block_size,bytes_per_wal_segment,max_identifier_length,max_index_columns,max_toast_chunk_size,large_object_chunk_size,float8_pass_by_value,data_page_checksum_version}',
   prosrc => 'pg_control_init' },
 
+# type subscripting support
+{ oid => '6098',
+  descr => 'Jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler',
+  prorettype => 'internal',
+  proargtypes => 'internal',
+  prosrc => 'jsonb_subscript_handler' },
+
 { oid => '6099',
   descr => 'Array subscripting logic',
   proname => 'array_subscript_handler',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 21489a02ae..fa7e1d22a5 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -456,7 +456,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubshandler => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..6e3b75d56a 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,6 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
+extern JsonbValue *to_jsonb_worker(Datum source, Oid source_type, bool is_null);
 
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..04a146a7d0 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4567,7 +4567,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4697,6 +4697,237 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+ERROR:  subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..12541e7e50 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1172,7 +1172,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1203,6 +1203,72 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--u66dlpg6gaevsofr
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v33-0004-Subscripting-documentation.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: erthalion @ 2019-02-01 10:41 UTC (permalink / raw)

Subscripting implementation for jsonb. For the sake of code reuse, some
parts of jsonb functionality were rearranged to allow use the same
functions for jsonb_set and assign subscripting operation.

Reviewed-by: Tom Lane, Arthur Zakirov
---
 src/backend/utils/adt/jsonb.c       |  27 ++-
 src/backend/utils/adt/jsonb_util.c  |  76 ++++++-
 src/backend/utils/adt/jsonfuncs.c   | 325 ++++++++++++++++++++--------
 src/include/catalog/pg_proc.dat     |   8 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   2 +
 src/test/regress/expected/jsonb.out | 233 +++++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  68 +++++-
 8 files changed, 632 insertions(+), 110 deletions(-)

diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 1e9ca046c6..f66642def3 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -1134,23 +1134,34 @@ to_jsonb(PG_FUNCTION_ARGS)
 {
 	Datum		val = PG_GETARG_DATUM(0);
 	Oid			val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
-	JsonbInState result;
-	JsonbTypeCategory tcategory;
-	Oid			outfuncoid;
+	JsonbValue *res = to_jsonb_worker(val, val_type, false);
+	PG_RETURN_POINTER(JsonbValueToJsonb(res));
+}
 
-	if (val_type == InvalidOid)
+/*
+ * Do the actual conversion to jsonb for to_jsonb function. This logic is
+ * separated because it can be useful not only in here (e.g. we use it in
+ * jsonb subscripting)
+ */
+JsonbValue *
+to_jsonb_worker(Datum source, Oid source_type, bool is_null)
+{
+	JsonbInState		result;
+	JsonbTypeCategory	tcategory;
+	Oid					outfuncoid;
+
+	if (source_type == InvalidOid)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("could not determine input data type")));
 
-	jsonb_categorize_type(val_type,
+	jsonb_categorize_type(source_type,
 						  &tcategory, &outfuncoid);
 
 	memset(&result, 0, sizeof(JsonbInState));
 
-	datum_to_jsonb(val, false, &result, tcategory, outfuncoid, false);
-
-	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
+	datum_to_jsonb(source, is_null, &result, tcategory, outfuncoid, false);
+	return result.res;
 }
 
 /*
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 5a09d65fdc..f46a2828b3 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -21,12 +21,16 @@
 #include "common/jsonapi.h"
 #include "fmgr.h"
 #include "funcapi.h"
+#include "executor/execExpr.h"
 #include "lib/stringinfo.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
+#include "parser/parse_coerce.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/hsearch.h"
+#include "utils/fmgroids.h"
 #include "utils/json.h"
 #include "utils/jsonb.h"
 #include "utils/jsonfuncs.h"
@@ -460,18 +464,22 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
+static Datum jsonb_set_element(Datum datum, Datum *path, int path_len,
+							   Datum sourceData, Oid source_type, bool is_null);
+static Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -486,6 +494,15 @@ static void transform_string_values_object_field_start(void *state, char *fname,
 static void transform_string_values_array_element_start(void *state, bool isnull);
 static void transform_string_values_scalar(void *state, char *token, JsonTokenType tokentype);
 
+static SubscriptingRef *jsonb_subscript_prepare(bool isAssignment,
+												SubscriptingRef *sbsref);
+
+static SubscriptingRef *jsonb_subscript_validate(bool isAssignment,
+												 SubscriptingRef *sbsref,
+												 ParseState *pstate);
+static Datum jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate);
+static Datum jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate);
+
 /*
  * pg_parse_json_or_ereport
  *
@@ -1447,13 +1464,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1468,9 +1481,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+static Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	Jsonb		   *res;
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	JsonbValue		tv;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1495,7 +1527,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1511,22 +1543,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1544,7 +1579,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1554,11 +1592,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1580,9 +1622,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1593,6 +1638,32 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Datum jsonbdatum, Datum *path, int path_len,
+				  Datum sourceData, Oid source_type, bool is_null)
+{
+	Jsonb			   *jb = DatumGetJsonbP(jsonbdatum);
+	JsonbValue		   *newval,
+					   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	newval = to_jsonb_worker(sourceData, source_type, is_null);
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4152,58 +4223,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4475,7 +4494,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4633,7 +4653,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4796,7 +4817,7 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 static JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4849,11 +4870,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4870,7 +4891,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4901,7 +4922,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4924,7 +4945,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4956,7 +4977,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5004,7 +5025,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5020,7 +5041,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5031,7 +5052,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5065,12 +5086,138 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
 }
 
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	return jsonb_get_element(DatumGetJsonbP(containerSource),
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 &sbstate->resnull,
+							 false);
+}
+
+
+
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	/*
+	 * the original jsonb must be non-NULL, else we punt and return the
+	 * original array.
+	 */
+	if (sbstate->resnull)
+		return containerSource;
+
+	return jsonb_set_element(containerSource,
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 sbstate->replacevalue,
+							 sbstate->refelemtype,
+							 sbstate->replacenull);
+}
+
+/*
+ * Perform preparation for the jsonb subscripting. Since there are not any
+ * particular restrictions for this kind of subscripting, we will verify that
+ * it is not a slice operation. This function produces an expression that
+ * represents the result of extracting a single container element or the new
+ * container value with the source data inserted into the right part of the
+ * container. If you have read until this point, and will submit a meaningful
+ * review of this patch series, I'll owe you a beer at the next PGConfEU.
+ */
+
+/*
+ * Handle jsonb-type subscripting logic.
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	SubscriptRoutines *sbsroutines = (SubscriptRoutines *)
+									 palloc(sizeof(SubscriptRoutines));
+
+	sbsroutines->prepare = jsonb_subscript_prepare;
+	sbsroutines->validate = jsonb_subscript_validate;
+	sbsroutines->fetch = jsonb_subscript_fetch;
+	sbsroutines->assign = jsonb_subscript_assign;
+
+	PG_RETURN_POINTER(sbsroutines);
+}
+
+SubscriptingRef *
+jsonb_subscript_prepare(bool isAssignment, SubscriptingRef *sbsref)
+{
+	if (isAssignment)
+	{
+		sbsref->refelemtype = exprType((Node *) sbsref->refassgnexpr);
+		sbsref->refassgntype = exprType((Node *) sbsref->refassgnexpr);
+	}
+	else
+		sbsref->refelemtype = JSONBOID;
+
+	return sbsref;
+}
+
+SubscriptingRef *
+jsonb_subscript_validate(bool isAssignment, SubscriptingRef *sbsref,
+						 ParseState *pstate)
+{
+	List			   *upperIndexpr = NIL;
+	ListCell		   *l;
+
+	if (sbsref->reflowerindexpr != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("jsonb subscript does not support slices"),
+				 parser_errposition(pstate, exprLocation(
+						 ((Node *) linitial(sbsref->reflowerindexpr))))));
+
+	foreach(l, sbsref->refupperindexpr)
+	{
+		Node *subexpr = (Node *) lfirst(l);
+
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(
+						((Node *) linitial(sbsref->refupperindexpr))))));
+
+		subexpr = coerce_to_target_type(pstate,
+										subexpr, exprType(subexpr),
+										TEXTOID, -1,
+										COERCION_ASSIGNMENT,
+										COERCE_IMPLICIT_CAST,
+										-1);
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript must have text type"),
+					 parser_errposition(pstate, exprLocation(subexpr))));
+
+		upperIndexpr = lappend(upperIndexpr, subexpr);
+	}
+
+	sbsref->refupperindexpr = upperIndexpr;
+
+	return sbsref;
+}
+
 /*
  * Parse information about what elements of a jsonb document we want to iterate
  * in functions iterate_json(b)_values. This information is presented in jsonb
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 8761597e12..bf0d4ef743 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10879,6 +10879,14 @@
   proargnames => '{max_data_alignment,database_block_size,blocks_per_segment,wal_block_size,bytes_per_wal_segment,max_identifier_length,max_index_columns,max_toast_chunk_size,large_object_chunk_size,float8_pass_by_value,data_page_checksum_version}',
   prosrc => 'pg_control_init' },
 
+# type subscripting support
+{ oid => '6098',
+  descr => 'Jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler',
+  prorettype => 'internal',
+  proargtypes => 'internal',
+  prosrc => 'jsonb_subscript_handler' },
+
 { oid => '6099',
   descr => 'Array subscripting logic',
   proname => 'array_subscript_handler',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 21489a02ae..fa7e1d22a5 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -456,7 +456,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubshandler => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..6e3b75d56a 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,6 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
+extern JsonbValue *to_jsonb_worker(Datum source, Oid source_type, bool is_null);
 
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..04a146a7d0 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4567,7 +4567,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4697,6 +4697,237 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+ERROR:  subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..12541e7e50 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1172,7 +1172,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1203,6 +1203,72 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--u66dlpg6gaevsofr
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v33-0004-Subscripting-documentation.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v31 3/6] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: erthalion @ 2019-02-01 10:41 UTC (permalink / raw)

Subscripting implementation for jsonb. For the sake of code reuse, some
parts of jsonb functionality were rearranged to allow use the same
functions for jsonb_set and assign subscripting operation.

Reviewed-by: Tom Lane, Arthur Zakirov
---
 src/backend/utils/adt/jsonb.c       |  27 ++-
 src/backend/utils/adt/jsonb_util.c  |  76 ++++++-
 src/backend/utils/adt/jsonfuncs.c   | 325 ++++++++++++++++++++--------
 src/include/catalog/pg_proc.dat     |   8 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   2 +
 src/test/regress/expected/jsonb.out | 233 +++++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  68 +++++-
 8 files changed, 632 insertions(+), 110 deletions(-)

diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 1e9ca046c6..f66642def3 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -1134,23 +1134,34 @@ to_jsonb(PG_FUNCTION_ARGS)
 {
 	Datum		val = PG_GETARG_DATUM(0);
 	Oid			val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
-	JsonbInState result;
-	JsonbTypeCategory tcategory;
-	Oid			outfuncoid;
+	JsonbValue *res = to_jsonb_worker(val, val_type, false);
+	PG_RETURN_POINTER(JsonbValueToJsonb(res));
+}
 
-	if (val_type == InvalidOid)
+/*
+ * Do the actual conversion to jsonb for to_jsonb function. This logic is
+ * separated because it can be useful not only in here (e.g. we use it in
+ * jsonb subscripting)
+ */
+JsonbValue *
+to_jsonb_worker(Datum source, Oid source_type, bool is_null)
+{
+	JsonbInState		result;
+	JsonbTypeCategory	tcategory;
+	Oid					outfuncoid;
+
+	if (source_type == InvalidOid)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("could not determine input data type")));
 
-	jsonb_categorize_type(val_type,
+	jsonb_categorize_type(source_type,
 						  &tcategory, &outfuncoid);
 
 	memset(&result, 0, sizeof(JsonbInState));
 
-	datum_to_jsonb(val, false, &result, tcategory, outfuncoid, false);
-
-	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
+	datum_to_jsonb(source, is_null, &result, tcategory, outfuncoid, false);
+	return result.res;
 }
 
 /*
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 04b70c805b..adcf16acf1 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 5a09d65fdc..f46a2828b3 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -21,12 +21,16 @@
 #include "common/jsonapi.h"
 #include "fmgr.h"
 #include "funcapi.h"
+#include "executor/execExpr.h"
 #include "lib/stringinfo.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
+#include "parser/parse_coerce.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/hsearch.h"
+#include "utils/fmgroids.h"
 #include "utils/json.h"
 #include "utils/jsonb.h"
 #include "utils/jsonfuncs.h"
@@ -460,18 +464,22 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
+static Datum jsonb_set_element(Datum datum, Datum *path, int path_len,
+							   Datum sourceData, Oid source_type, bool is_null);
+static Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -486,6 +494,15 @@ static void transform_string_values_object_field_start(void *state, char *fname,
 static void transform_string_values_array_element_start(void *state, bool isnull);
 static void transform_string_values_scalar(void *state, char *token, JsonTokenType tokentype);
 
+static SubscriptingRef *jsonb_subscript_prepare(bool isAssignment,
+												SubscriptingRef *sbsref);
+
+static SubscriptingRef *jsonb_subscript_validate(bool isAssignment,
+												 SubscriptingRef *sbsref,
+												 ParseState *pstate);
+static Datum jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate);
+static Datum jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate);
+
 /*
  * pg_parse_json_or_ereport
  *
@@ -1447,13 +1464,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1468,9 +1481,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+static Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	Jsonb		   *res;
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	JsonbValue		tv;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1495,7 +1527,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1511,22 +1543,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1544,7 +1579,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1554,11 +1592,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1580,9 +1622,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1593,6 +1638,32 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Datum jsonbdatum, Datum *path, int path_len,
+				  Datum sourceData, Oid source_type, bool is_null)
+{
+	Jsonb			   *jb = DatumGetJsonbP(jsonbdatum);
+	JsonbValue		   *newval,
+					   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	newval = to_jsonb_worker(sourceData, source_type, is_null);
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4152,58 +4223,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4475,7 +4494,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4633,7 +4653,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4796,7 +4817,7 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 static JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4849,11 +4870,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4870,7 +4891,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4901,7 +4922,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4924,7 +4945,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4956,7 +4977,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5004,7 +5025,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5020,7 +5041,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5031,7 +5052,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5065,12 +5086,138 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
 }
 
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	return jsonb_get_element(DatumGetJsonbP(containerSource),
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 &sbstate->resnull,
+							 false);
+}
+
+
+
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	/*
+	 * the original jsonb must be non-NULL, else we punt and return the
+	 * original array.
+	 */
+	if (sbstate->resnull)
+		return containerSource;
+
+	return jsonb_set_element(containerSource,
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 sbstate->replacevalue,
+							 sbstate->refelemtype,
+							 sbstate->replacenull);
+}
+
+/*
+ * Perform preparation for the jsonb subscripting. Since there are not any
+ * particular restrictions for this kind of subscripting, we will verify that
+ * it is not a slice operation. This function produces an expression that
+ * represents the result of extracting a single container element or the new
+ * container value with the source data inserted into the right part of the
+ * container. If you have read until this point, and will submit a meaningful
+ * review of this patch series, I'll owe you a beer at the next PGConfEU.
+ */
+
+/*
+ * Handle jsonb-type subscripting logic.
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	SubscriptRoutines *sbsroutines = (SubscriptRoutines *)
+									 palloc(sizeof(SubscriptRoutines));
+
+	sbsroutines->prepare = jsonb_subscript_prepare;
+	sbsroutines->validate = jsonb_subscript_validate;
+	sbsroutines->fetch = jsonb_subscript_fetch;
+	sbsroutines->assign = jsonb_subscript_assign;
+
+	PG_RETURN_POINTER(sbsroutines);
+}
+
+SubscriptingRef *
+jsonb_subscript_prepare(bool isAssignment, SubscriptingRef *sbsref)
+{
+	if (isAssignment)
+	{
+		sbsref->refelemtype = exprType((Node *) sbsref->refassgnexpr);
+		sbsref->refassgntype = exprType((Node *) sbsref->refassgnexpr);
+	}
+	else
+		sbsref->refelemtype = JSONBOID;
+
+	return sbsref;
+}
+
+SubscriptingRef *
+jsonb_subscript_validate(bool isAssignment, SubscriptingRef *sbsref,
+						 ParseState *pstate)
+{
+	List			   *upperIndexpr = NIL;
+	ListCell		   *l;
+
+	if (sbsref->reflowerindexpr != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("jsonb subscript does not support slices"),
+				 parser_errposition(pstate, exprLocation(
+						 ((Node *) linitial(sbsref->reflowerindexpr))))));
+
+	foreach(l, sbsref->refupperindexpr)
+	{
+		Node *subexpr = (Node *) lfirst(l);
+
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(
+						((Node *) linitial(sbsref->refupperindexpr))))));
+
+		subexpr = coerce_to_target_type(pstate,
+										subexpr, exprType(subexpr),
+										TEXTOID, -1,
+										COERCION_ASSIGNMENT,
+										COERCE_IMPLICIT_CAST,
+										-1);
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript must have text type"),
+					 parser_errposition(pstate, exprLocation(subexpr))));
+
+		upperIndexpr = lappend(upperIndexpr, subexpr);
+	}
+
+	sbsref->refupperindexpr = upperIndexpr;
+
+	return sbsref;
+}
+
 /*
  * Parse information about what elements of a jsonb document we want to iterate
  * in functions iterate_json(b)_values. This information is presented in jsonb
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index ba9c61307e..6f73d8ecc8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10862,6 +10862,14 @@
   proargnames => '{max_data_alignment,database_block_size,blocks_per_segment,wal_block_size,bytes_per_wal_segment,max_identifier_length,max_index_columns,max_toast_chunk_size,large_object_chunk_size,float8_pass_by_value,data_page_checksum_version}',
   prosrc => 'pg_control_init' },
 
+# type subscripting support
+{ oid => '4226',
+  descr => 'Jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler',
+  prorettype => 'internal',
+  proargtypes => 'internal',
+  prosrc => 'jsonb_subscript_handler' },
+
 { oid => '4225',
   descr => 'Array subscripting logic',
   proname => 'array_subscript_handler',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index c151c0b37b..6286461be5 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -456,7 +456,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubshandler => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..6e3b75d56a 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,6 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
+extern JsonbValue *to_jsonb_worker(Datum source, Oid source_type, bool is_null);
 
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..04a146a7d0 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4567,7 +4567,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4697,6 +4697,237 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+ERROR:  subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..12541e7e50 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1172,7 +1172,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1203,6 +1203,72 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--bvn7grlx53cj2mie
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v31-0004-Subscripting-documentation.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: erthalion @ 2019-02-01 10:41 UTC (permalink / raw)

Subscripting implementation for jsonb. For the sake of code reuse, some
parts of jsonb functionality were rearranged to allow use the same
functions for jsonb_set and assign subscripting operation.

Reviewed-by: Tom Lane, Arthur Zakirov
---
 src/backend/utils/adt/jsonb.c       |  27 ++-
 src/backend/utils/adt/jsonb_util.c  |  76 ++++++-
 src/backend/utils/adt/jsonfuncs.c   | 325 ++++++++++++++++++++--------
 src/include/catalog/pg_proc.dat     |   8 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   2 +
 src/test/regress/expected/jsonb.out | 233 +++++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  68 +++++-
 8 files changed, 632 insertions(+), 110 deletions(-)

diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 1e9ca046c6..f66642def3 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -1134,23 +1134,34 @@ to_jsonb(PG_FUNCTION_ARGS)
 {
 	Datum		val = PG_GETARG_DATUM(0);
 	Oid			val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
-	JsonbInState result;
-	JsonbTypeCategory tcategory;
-	Oid			outfuncoid;
+	JsonbValue *res = to_jsonb_worker(val, val_type, false);
+	PG_RETURN_POINTER(JsonbValueToJsonb(res));
+}
 
-	if (val_type == InvalidOid)
+/*
+ * Do the actual conversion to jsonb for to_jsonb function. This logic is
+ * separated because it can be useful not only in here (e.g. we use it in
+ * jsonb subscripting)
+ */
+JsonbValue *
+to_jsonb_worker(Datum source, Oid source_type, bool is_null)
+{
+	JsonbInState		result;
+	JsonbTypeCategory	tcategory;
+	Oid					outfuncoid;
+
+	if (source_type == InvalidOid)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("could not determine input data type")));
 
-	jsonb_categorize_type(val_type,
+	jsonb_categorize_type(source_type,
 						  &tcategory, &outfuncoid);
 
 	memset(&result, 0, sizeof(JsonbInState));
 
-	datum_to_jsonb(val, false, &result, tcategory, outfuncoid, false);
-
-	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
+	datum_to_jsonb(source, is_null, &result, tcategory, outfuncoid, false);
+	return result.res;
 }
 
 /*
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 5a09d65fdc..f46a2828b3 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -21,12 +21,16 @@
 #include "common/jsonapi.h"
 #include "fmgr.h"
 #include "funcapi.h"
+#include "executor/execExpr.h"
 #include "lib/stringinfo.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
+#include "parser/parse_coerce.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/hsearch.h"
+#include "utils/fmgroids.h"
 #include "utils/json.h"
 #include "utils/jsonb.h"
 #include "utils/jsonfuncs.h"
@@ -460,18 +464,22 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
+static Datum jsonb_set_element(Datum datum, Datum *path, int path_len,
+							   Datum sourceData, Oid source_type, bool is_null);
+static Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -486,6 +494,15 @@ static void transform_string_values_object_field_start(void *state, char *fname,
 static void transform_string_values_array_element_start(void *state, bool isnull);
 static void transform_string_values_scalar(void *state, char *token, JsonTokenType tokentype);
 
+static SubscriptingRef *jsonb_subscript_prepare(bool isAssignment,
+												SubscriptingRef *sbsref);
+
+static SubscriptingRef *jsonb_subscript_validate(bool isAssignment,
+												 SubscriptingRef *sbsref,
+												 ParseState *pstate);
+static Datum jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate);
+static Datum jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate);
+
 /*
  * pg_parse_json_or_ereport
  *
@@ -1447,13 +1464,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1468,9 +1481,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+static Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	Jsonb		   *res;
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	JsonbValue		tv;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1495,7 +1527,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1511,22 +1543,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1544,7 +1579,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1554,11 +1592,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1580,9 +1622,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1593,6 +1638,32 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Datum jsonbdatum, Datum *path, int path_len,
+				  Datum sourceData, Oid source_type, bool is_null)
+{
+	Jsonb			   *jb = DatumGetJsonbP(jsonbdatum);
+	JsonbValue		   *newval,
+					   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	newval = to_jsonb_worker(sourceData, source_type, is_null);
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4152,58 +4223,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4475,7 +4494,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4633,7 +4653,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4796,7 +4817,7 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 static JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4849,11 +4870,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4870,7 +4891,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4901,7 +4922,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4924,7 +4945,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4956,7 +4977,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5004,7 +5025,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5020,7 +5041,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5031,7 +5052,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5065,12 +5086,138 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
 }
 
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	return jsonb_get_element(DatumGetJsonbP(containerSource),
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 &sbstate->resnull,
+							 false);
+}
+
+
+
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	/*
+	 * the original jsonb must be non-NULL, else we punt and return the
+	 * original array.
+	 */
+	if (sbstate->resnull)
+		return containerSource;
+
+	return jsonb_set_element(containerSource,
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 sbstate->replacevalue,
+							 sbstate->refelemtype,
+							 sbstate->replacenull);
+}
+
+/*
+ * Perform preparation for the jsonb subscripting. Since there are not any
+ * particular restrictions for this kind of subscripting, we will verify that
+ * it is not a slice operation. This function produces an expression that
+ * represents the result of extracting a single container element or the new
+ * container value with the source data inserted into the right part of the
+ * container. If you have read until this point, and will submit a meaningful
+ * review of this patch series, I'll owe you a beer at the next PGConfEU.
+ */
+
+/*
+ * Handle jsonb-type subscripting logic.
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	SubscriptRoutines *sbsroutines = (SubscriptRoutines *)
+									 palloc(sizeof(SubscriptRoutines));
+
+	sbsroutines->prepare = jsonb_subscript_prepare;
+	sbsroutines->validate = jsonb_subscript_validate;
+	sbsroutines->fetch = jsonb_subscript_fetch;
+	sbsroutines->assign = jsonb_subscript_assign;
+
+	PG_RETURN_POINTER(sbsroutines);
+}
+
+SubscriptingRef *
+jsonb_subscript_prepare(bool isAssignment, SubscriptingRef *sbsref)
+{
+	if (isAssignment)
+	{
+		sbsref->refelemtype = exprType((Node *) sbsref->refassgnexpr);
+		sbsref->refassgntype = exprType((Node *) sbsref->refassgnexpr);
+	}
+	else
+		sbsref->refelemtype = JSONBOID;
+
+	return sbsref;
+}
+
+SubscriptingRef *
+jsonb_subscript_validate(bool isAssignment, SubscriptingRef *sbsref,
+						 ParseState *pstate)
+{
+	List			   *upperIndexpr = NIL;
+	ListCell		   *l;
+
+	if (sbsref->reflowerindexpr != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("jsonb subscript does not support slices"),
+				 parser_errposition(pstate, exprLocation(
+						 ((Node *) linitial(sbsref->reflowerindexpr))))));
+
+	foreach(l, sbsref->refupperindexpr)
+	{
+		Node *subexpr = (Node *) lfirst(l);
+
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(
+						((Node *) linitial(sbsref->refupperindexpr))))));
+
+		subexpr = coerce_to_target_type(pstate,
+										subexpr, exprType(subexpr),
+										TEXTOID, -1,
+										COERCION_ASSIGNMENT,
+										COERCE_IMPLICIT_CAST,
+										-1);
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript must have text type"),
+					 parser_errposition(pstate, exprLocation(subexpr))));
+
+		upperIndexpr = lappend(upperIndexpr, subexpr);
+	}
+
+	sbsref->refupperindexpr = upperIndexpr;
+
+	return sbsref;
+}
+
 /*
  * Parse information about what elements of a jsonb document we want to iterate
  * in functions iterate_json(b)_values. This information is presented in jsonb
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 8761597e12..bf0d4ef743 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10879,6 +10879,14 @@
   proargnames => '{max_data_alignment,database_block_size,blocks_per_segment,wal_block_size,bytes_per_wal_segment,max_identifier_length,max_index_columns,max_toast_chunk_size,large_object_chunk_size,float8_pass_by_value,data_page_checksum_version}',
   prosrc => 'pg_control_init' },
 
+# type subscripting support
+{ oid => '6098',
+  descr => 'Jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler',
+  prorettype => 'internal',
+  proargtypes => 'internal',
+  prosrc => 'jsonb_subscript_handler' },
+
 { oid => '6099',
   descr => 'Array subscripting logic',
   proname => 'array_subscript_handler',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 21489a02ae..fa7e1d22a5 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -456,7 +456,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubshandler => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..6e3b75d56a 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,6 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
+extern JsonbValue *to_jsonb_worker(Datum source, Oid source_type, bool is_null);
 
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..04a146a7d0 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4567,7 +4567,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4697,6 +4697,237 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+ERROR:  subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..12541e7e50 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1172,7 +1172,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1203,6 +1203,72 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--u66dlpg6gaevsofr
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v33-0004-Subscripting-documentation.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: erthalion @ 2019-02-01 10:41 UTC (permalink / raw)

Subscripting implementation for jsonb. For the sake of code reuse, some
parts of jsonb functionality were rearranged to allow use the same
functions for jsonb_set and assign subscripting operation.

Reviewed-by: Tom Lane, Arthur Zakirov
---
 src/backend/utils/adt/jsonb.c       |  27 ++-
 src/backend/utils/adt/jsonb_util.c  |  76 ++++++-
 src/backend/utils/adt/jsonfuncs.c   | 325 ++++++++++++++++++++--------
 src/include/catalog/pg_proc.dat     |   8 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   2 +
 src/test/regress/expected/jsonb.out | 233 +++++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  68 +++++-
 8 files changed, 632 insertions(+), 110 deletions(-)

diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 1e9ca046c6..f66642def3 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -1134,23 +1134,34 @@ to_jsonb(PG_FUNCTION_ARGS)
 {
 	Datum		val = PG_GETARG_DATUM(0);
 	Oid			val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
-	JsonbInState result;
-	JsonbTypeCategory tcategory;
-	Oid			outfuncoid;
+	JsonbValue *res = to_jsonb_worker(val, val_type, false);
+	PG_RETURN_POINTER(JsonbValueToJsonb(res));
+}
 
-	if (val_type == InvalidOid)
+/*
+ * Do the actual conversion to jsonb for to_jsonb function. This logic is
+ * separated because it can be useful not only in here (e.g. we use it in
+ * jsonb subscripting)
+ */
+JsonbValue *
+to_jsonb_worker(Datum source, Oid source_type, bool is_null)
+{
+	JsonbInState		result;
+	JsonbTypeCategory	tcategory;
+	Oid					outfuncoid;
+
+	if (source_type == InvalidOid)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("could not determine input data type")));
 
-	jsonb_categorize_type(val_type,
+	jsonb_categorize_type(source_type,
 						  &tcategory, &outfuncoid);
 
 	memset(&result, 0, sizeof(JsonbInState));
 
-	datum_to_jsonb(val, false, &result, tcategory, outfuncoid, false);
-
-	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
+	datum_to_jsonb(source, is_null, &result, tcategory, outfuncoid, false);
+	return result.res;
 }
 
 /*
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 5a09d65fdc..f46a2828b3 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -21,12 +21,16 @@
 #include "common/jsonapi.h"
 #include "fmgr.h"
 #include "funcapi.h"
+#include "executor/execExpr.h"
 #include "lib/stringinfo.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
+#include "parser/parse_coerce.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/hsearch.h"
+#include "utils/fmgroids.h"
 #include "utils/json.h"
 #include "utils/jsonb.h"
 #include "utils/jsonfuncs.h"
@@ -460,18 +464,22 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
+static Datum jsonb_set_element(Datum datum, Datum *path, int path_len,
+							   Datum sourceData, Oid source_type, bool is_null);
+static Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -486,6 +494,15 @@ static void transform_string_values_object_field_start(void *state, char *fname,
 static void transform_string_values_array_element_start(void *state, bool isnull);
 static void transform_string_values_scalar(void *state, char *token, JsonTokenType tokentype);
 
+static SubscriptingRef *jsonb_subscript_prepare(bool isAssignment,
+												SubscriptingRef *sbsref);
+
+static SubscriptingRef *jsonb_subscript_validate(bool isAssignment,
+												 SubscriptingRef *sbsref,
+												 ParseState *pstate);
+static Datum jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate);
+static Datum jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate);
+
 /*
  * pg_parse_json_or_ereport
  *
@@ -1447,13 +1464,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1468,9 +1481,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+static Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	Jsonb		   *res;
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	JsonbValue		tv;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1495,7 +1527,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1511,22 +1543,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1544,7 +1579,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1554,11 +1592,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1580,9 +1622,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1593,6 +1638,32 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Datum jsonbdatum, Datum *path, int path_len,
+				  Datum sourceData, Oid source_type, bool is_null)
+{
+	Jsonb			   *jb = DatumGetJsonbP(jsonbdatum);
+	JsonbValue		   *newval,
+					   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	newval = to_jsonb_worker(sourceData, source_type, is_null);
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4152,58 +4223,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4475,7 +4494,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4633,7 +4653,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4796,7 +4817,7 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 static JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4849,11 +4870,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4870,7 +4891,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4901,7 +4922,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4924,7 +4945,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4956,7 +4977,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5004,7 +5025,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5020,7 +5041,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5031,7 +5052,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5065,12 +5086,138 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
 }
 
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	return jsonb_get_element(DatumGetJsonbP(containerSource),
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 &sbstate->resnull,
+							 false);
+}
+
+
+
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	/*
+	 * the original jsonb must be non-NULL, else we punt and return the
+	 * original array.
+	 */
+	if (sbstate->resnull)
+		return containerSource;
+
+	return jsonb_set_element(containerSource,
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 sbstate->replacevalue,
+							 sbstate->refelemtype,
+							 sbstate->replacenull);
+}
+
+/*
+ * Perform preparation for the jsonb subscripting. Since there are not any
+ * particular restrictions for this kind of subscripting, we will verify that
+ * it is not a slice operation. This function produces an expression that
+ * represents the result of extracting a single container element or the new
+ * container value with the source data inserted into the right part of the
+ * container. If you have read until this point, and will submit a meaningful
+ * review of this patch series, I'll owe you a beer at the next PGConfEU.
+ */
+
+/*
+ * Handle jsonb-type subscripting logic.
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	SubscriptRoutines *sbsroutines = (SubscriptRoutines *)
+									 palloc(sizeof(SubscriptRoutines));
+
+	sbsroutines->prepare = jsonb_subscript_prepare;
+	sbsroutines->validate = jsonb_subscript_validate;
+	sbsroutines->fetch = jsonb_subscript_fetch;
+	sbsroutines->assign = jsonb_subscript_assign;
+
+	PG_RETURN_POINTER(sbsroutines);
+}
+
+SubscriptingRef *
+jsonb_subscript_prepare(bool isAssignment, SubscriptingRef *sbsref)
+{
+	if (isAssignment)
+	{
+		sbsref->refelemtype = exprType((Node *) sbsref->refassgnexpr);
+		sbsref->refassgntype = exprType((Node *) sbsref->refassgnexpr);
+	}
+	else
+		sbsref->refelemtype = JSONBOID;
+
+	return sbsref;
+}
+
+SubscriptingRef *
+jsonb_subscript_validate(bool isAssignment, SubscriptingRef *sbsref,
+						 ParseState *pstate)
+{
+	List			   *upperIndexpr = NIL;
+	ListCell		   *l;
+
+	if (sbsref->reflowerindexpr != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("jsonb subscript does not support slices"),
+				 parser_errposition(pstate, exprLocation(
+						 ((Node *) linitial(sbsref->reflowerindexpr))))));
+
+	foreach(l, sbsref->refupperindexpr)
+	{
+		Node *subexpr = (Node *) lfirst(l);
+
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(
+						((Node *) linitial(sbsref->refupperindexpr))))));
+
+		subexpr = coerce_to_target_type(pstate,
+										subexpr, exprType(subexpr),
+										TEXTOID, -1,
+										COERCION_ASSIGNMENT,
+										COERCE_IMPLICIT_CAST,
+										-1);
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript must have text type"),
+					 parser_errposition(pstate, exprLocation(subexpr))));
+
+		upperIndexpr = lappend(upperIndexpr, subexpr);
+	}
+
+	sbsref->refupperindexpr = upperIndexpr;
+
+	return sbsref;
+}
+
 /*
  * Parse information about what elements of a jsonb document we want to iterate
  * in functions iterate_json(b)_values. This information is presented in jsonb
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 8761597e12..bf0d4ef743 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10879,6 +10879,14 @@
   proargnames => '{max_data_alignment,database_block_size,blocks_per_segment,wal_block_size,bytes_per_wal_segment,max_identifier_length,max_index_columns,max_toast_chunk_size,large_object_chunk_size,float8_pass_by_value,data_page_checksum_version}',
   prosrc => 'pg_control_init' },
 
+# type subscripting support
+{ oid => '6098',
+  descr => 'Jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler',
+  prorettype => 'internal',
+  proargtypes => 'internal',
+  prosrc => 'jsonb_subscript_handler' },
+
 { oid => '6099',
   descr => 'Array subscripting logic',
   proname => 'array_subscript_handler',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 21489a02ae..fa7e1d22a5 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -456,7 +456,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubshandler => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..6e3b75d56a 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,6 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
+extern JsonbValue *to_jsonb_worker(Datum source, Oid source_type, bool is_null);
 
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..04a146a7d0 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4567,7 +4567,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4697,6 +4697,237 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+ERROR:  subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..12541e7e50 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1172,7 +1172,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1203,6 +1203,72 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--u66dlpg6gaevsofr
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v33-0004-Subscripting-documentation.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: erthalion @ 2019-02-01 10:41 UTC (permalink / raw)

Subscripting implementation for jsonb. For the sake of code reuse, some
parts of jsonb functionality were rearranged to allow use the same
functions for jsonb_set and assign subscripting operation.

Reviewed-by: Tom Lane, Arthur Zakirov
---
 src/backend/utils/adt/jsonb.c       |  27 ++-
 src/backend/utils/adt/jsonb_util.c  |  76 ++++++-
 src/backend/utils/adt/jsonfuncs.c   | 325 ++++++++++++++++++++--------
 src/include/catalog/pg_proc.dat     |   8 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   2 +
 src/test/regress/expected/jsonb.out | 233 +++++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  68 +++++-
 8 files changed, 632 insertions(+), 110 deletions(-)

diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 1e9ca046c6..f66642def3 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -1134,23 +1134,34 @@ to_jsonb(PG_FUNCTION_ARGS)
 {
 	Datum		val = PG_GETARG_DATUM(0);
 	Oid			val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
-	JsonbInState result;
-	JsonbTypeCategory tcategory;
-	Oid			outfuncoid;
+	JsonbValue *res = to_jsonb_worker(val, val_type, false);
+	PG_RETURN_POINTER(JsonbValueToJsonb(res));
+}
 
-	if (val_type == InvalidOid)
+/*
+ * Do the actual conversion to jsonb for to_jsonb function. This logic is
+ * separated because it can be useful not only in here (e.g. we use it in
+ * jsonb subscripting)
+ */
+JsonbValue *
+to_jsonb_worker(Datum source, Oid source_type, bool is_null)
+{
+	JsonbInState		result;
+	JsonbTypeCategory	tcategory;
+	Oid					outfuncoid;
+
+	if (source_type == InvalidOid)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("could not determine input data type")));
 
-	jsonb_categorize_type(val_type,
+	jsonb_categorize_type(source_type,
 						  &tcategory, &outfuncoid);
 
 	memset(&result, 0, sizeof(JsonbInState));
 
-	datum_to_jsonb(val, false, &result, tcategory, outfuncoid, false);
-
-	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
+	datum_to_jsonb(source, is_null, &result, tcategory, outfuncoid, false);
+	return result.res;
 }
 
 /*
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 5a09d65fdc..f46a2828b3 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -21,12 +21,16 @@
 #include "common/jsonapi.h"
 #include "fmgr.h"
 #include "funcapi.h"
+#include "executor/execExpr.h"
 #include "lib/stringinfo.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
+#include "parser/parse_coerce.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/hsearch.h"
+#include "utils/fmgroids.h"
 #include "utils/json.h"
 #include "utils/jsonb.h"
 #include "utils/jsonfuncs.h"
@@ -460,18 +464,22 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
+static Datum jsonb_set_element(Datum datum, Datum *path, int path_len,
+							   Datum sourceData, Oid source_type, bool is_null);
+static Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -486,6 +494,15 @@ static void transform_string_values_object_field_start(void *state, char *fname,
 static void transform_string_values_array_element_start(void *state, bool isnull);
 static void transform_string_values_scalar(void *state, char *token, JsonTokenType tokentype);
 
+static SubscriptingRef *jsonb_subscript_prepare(bool isAssignment,
+												SubscriptingRef *sbsref);
+
+static SubscriptingRef *jsonb_subscript_validate(bool isAssignment,
+												 SubscriptingRef *sbsref,
+												 ParseState *pstate);
+static Datum jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate);
+static Datum jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate);
+
 /*
  * pg_parse_json_or_ereport
  *
@@ -1447,13 +1464,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1468,9 +1481,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+static Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	Jsonb		   *res;
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	JsonbValue		tv;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1495,7 +1527,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1511,22 +1543,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1544,7 +1579,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1554,11 +1592,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1580,9 +1622,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1593,6 +1638,32 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Datum jsonbdatum, Datum *path, int path_len,
+				  Datum sourceData, Oid source_type, bool is_null)
+{
+	Jsonb			   *jb = DatumGetJsonbP(jsonbdatum);
+	JsonbValue		   *newval,
+					   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	newval = to_jsonb_worker(sourceData, source_type, is_null);
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4152,58 +4223,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4475,7 +4494,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4633,7 +4653,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4796,7 +4817,7 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 static JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4849,11 +4870,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4870,7 +4891,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4901,7 +4922,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4924,7 +4945,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4956,7 +4977,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5004,7 +5025,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5020,7 +5041,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5031,7 +5052,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5065,12 +5086,138 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
 }
 
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	return jsonb_get_element(DatumGetJsonbP(containerSource),
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 &sbstate->resnull,
+							 false);
+}
+
+
+
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	/*
+	 * the original jsonb must be non-NULL, else we punt and return the
+	 * original array.
+	 */
+	if (sbstate->resnull)
+		return containerSource;
+
+	return jsonb_set_element(containerSource,
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 sbstate->replacevalue,
+							 sbstate->refelemtype,
+							 sbstate->replacenull);
+}
+
+/*
+ * Perform preparation for the jsonb subscripting. Since there are not any
+ * particular restrictions for this kind of subscripting, we will verify that
+ * it is not a slice operation. This function produces an expression that
+ * represents the result of extracting a single container element or the new
+ * container value with the source data inserted into the right part of the
+ * container. If you have read until this point, and will submit a meaningful
+ * review of this patch series, I'll owe you a beer at the next PGConfEU.
+ */
+
+/*
+ * Handle jsonb-type subscripting logic.
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	SubscriptRoutines *sbsroutines = (SubscriptRoutines *)
+									 palloc(sizeof(SubscriptRoutines));
+
+	sbsroutines->prepare = jsonb_subscript_prepare;
+	sbsroutines->validate = jsonb_subscript_validate;
+	sbsroutines->fetch = jsonb_subscript_fetch;
+	sbsroutines->assign = jsonb_subscript_assign;
+
+	PG_RETURN_POINTER(sbsroutines);
+}
+
+SubscriptingRef *
+jsonb_subscript_prepare(bool isAssignment, SubscriptingRef *sbsref)
+{
+	if (isAssignment)
+	{
+		sbsref->refelemtype = exprType((Node *) sbsref->refassgnexpr);
+		sbsref->refassgntype = exprType((Node *) sbsref->refassgnexpr);
+	}
+	else
+		sbsref->refelemtype = JSONBOID;
+
+	return sbsref;
+}
+
+SubscriptingRef *
+jsonb_subscript_validate(bool isAssignment, SubscriptingRef *sbsref,
+						 ParseState *pstate)
+{
+	List			   *upperIndexpr = NIL;
+	ListCell		   *l;
+
+	if (sbsref->reflowerindexpr != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("jsonb subscript does not support slices"),
+				 parser_errposition(pstate, exprLocation(
+						 ((Node *) linitial(sbsref->reflowerindexpr))))));
+
+	foreach(l, sbsref->refupperindexpr)
+	{
+		Node *subexpr = (Node *) lfirst(l);
+
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(
+						((Node *) linitial(sbsref->refupperindexpr))))));
+
+		subexpr = coerce_to_target_type(pstate,
+										subexpr, exprType(subexpr),
+										TEXTOID, -1,
+										COERCION_ASSIGNMENT,
+										COERCE_IMPLICIT_CAST,
+										-1);
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript must have text type"),
+					 parser_errposition(pstate, exprLocation(subexpr))));
+
+		upperIndexpr = lappend(upperIndexpr, subexpr);
+	}
+
+	sbsref->refupperindexpr = upperIndexpr;
+
+	return sbsref;
+}
+
 /*
  * Parse information about what elements of a jsonb document we want to iterate
  * in functions iterate_json(b)_values. This information is presented in jsonb
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 8761597e12..bf0d4ef743 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10879,6 +10879,14 @@
   proargnames => '{max_data_alignment,database_block_size,blocks_per_segment,wal_block_size,bytes_per_wal_segment,max_identifier_length,max_index_columns,max_toast_chunk_size,large_object_chunk_size,float8_pass_by_value,data_page_checksum_version}',
   prosrc => 'pg_control_init' },
 
+# type subscripting support
+{ oid => '6098',
+  descr => 'Jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler',
+  prorettype => 'internal',
+  proargtypes => 'internal',
+  prosrc => 'jsonb_subscript_handler' },
+
 { oid => '6099',
   descr => 'Array subscripting logic',
   proname => 'array_subscript_handler',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 21489a02ae..fa7e1d22a5 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -456,7 +456,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubshandler => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..6e3b75d56a 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,6 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
+extern JsonbValue *to_jsonb_worker(Datum source, Oid source_type, bool is_null);
 
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..04a146a7d0 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4567,7 +4567,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4697,6 +4697,237 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+ERROR:  subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..12541e7e50 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1172,7 +1172,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1203,6 +1203,72 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--u66dlpg6gaevsofr
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v33-0004-Subscripting-documentation.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: erthalion @ 2019-02-01 10:41 UTC (permalink / raw)

Subscripting implementation for jsonb. For the sake of code reuse, some
parts of jsonb functionality were rearranged to allow use the same
functions for jsonb_set and assign subscripting operation.

Reviewed-by: Tom Lane, Arthur Zakirov
---
 src/backend/utils/adt/jsonb.c       |  27 ++-
 src/backend/utils/adt/jsonb_util.c  |  76 ++++++-
 src/backend/utils/adt/jsonfuncs.c   | 325 ++++++++++++++++++++--------
 src/include/catalog/pg_proc.dat     |   8 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   2 +
 src/test/regress/expected/jsonb.out | 233 +++++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  68 +++++-
 8 files changed, 632 insertions(+), 110 deletions(-)

diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 1e9ca046c6..f66642def3 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -1134,23 +1134,34 @@ to_jsonb(PG_FUNCTION_ARGS)
 {
 	Datum		val = PG_GETARG_DATUM(0);
 	Oid			val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
-	JsonbInState result;
-	JsonbTypeCategory tcategory;
-	Oid			outfuncoid;
+	JsonbValue *res = to_jsonb_worker(val, val_type, false);
+	PG_RETURN_POINTER(JsonbValueToJsonb(res));
+}
 
-	if (val_type == InvalidOid)
+/*
+ * Do the actual conversion to jsonb for to_jsonb function. This logic is
+ * separated because it can be useful not only in here (e.g. we use it in
+ * jsonb subscripting)
+ */
+JsonbValue *
+to_jsonb_worker(Datum source, Oid source_type, bool is_null)
+{
+	JsonbInState		result;
+	JsonbTypeCategory	tcategory;
+	Oid					outfuncoid;
+
+	if (source_type == InvalidOid)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("could not determine input data type")));
 
-	jsonb_categorize_type(val_type,
+	jsonb_categorize_type(source_type,
 						  &tcategory, &outfuncoid);
 
 	memset(&result, 0, sizeof(JsonbInState));
 
-	datum_to_jsonb(val, false, &result, tcategory, outfuncoid, false);
-
-	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
+	datum_to_jsonb(source, is_null, &result, tcategory, outfuncoid, false);
+	return result.res;
 }
 
 /*
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 5a09d65fdc..f46a2828b3 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -21,12 +21,16 @@
 #include "common/jsonapi.h"
 #include "fmgr.h"
 #include "funcapi.h"
+#include "executor/execExpr.h"
 #include "lib/stringinfo.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
+#include "parser/parse_coerce.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/hsearch.h"
+#include "utils/fmgroids.h"
 #include "utils/json.h"
 #include "utils/jsonb.h"
 #include "utils/jsonfuncs.h"
@@ -460,18 +464,22 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
+static Datum jsonb_set_element(Datum datum, Datum *path, int path_len,
+							   Datum sourceData, Oid source_type, bool is_null);
+static Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -486,6 +494,15 @@ static void transform_string_values_object_field_start(void *state, char *fname,
 static void transform_string_values_array_element_start(void *state, bool isnull);
 static void transform_string_values_scalar(void *state, char *token, JsonTokenType tokentype);
 
+static SubscriptingRef *jsonb_subscript_prepare(bool isAssignment,
+												SubscriptingRef *sbsref);
+
+static SubscriptingRef *jsonb_subscript_validate(bool isAssignment,
+												 SubscriptingRef *sbsref,
+												 ParseState *pstate);
+static Datum jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate);
+static Datum jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate);
+
 /*
  * pg_parse_json_or_ereport
  *
@@ -1447,13 +1464,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1468,9 +1481,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+static Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	Jsonb		   *res;
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	JsonbValue		tv;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1495,7 +1527,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1511,22 +1543,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1544,7 +1579,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1554,11 +1592,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1580,9 +1622,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1593,6 +1638,32 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Datum jsonbdatum, Datum *path, int path_len,
+				  Datum sourceData, Oid source_type, bool is_null)
+{
+	Jsonb			   *jb = DatumGetJsonbP(jsonbdatum);
+	JsonbValue		   *newval,
+					   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	newval = to_jsonb_worker(sourceData, source_type, is_null);
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4152,58 +4223,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4475,7 +4494,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4633,7 +4653,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4796,7 +4817,7 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 static JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4849,11 +4870,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4870,7 +4891,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4901,7 +4922,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4924,7 +4945,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4956,7 +4977,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5004,7 +5025,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5020,7 +5041,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5031,7 +5052,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5065,12 +5086,138 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
 }
 
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	return jsonb_get_element(DatumGetJsonbP(containerSource),
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 &sbstate->resnull,
+							 false);
+}
+
+
+
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	/*
+	 * the original jsonb must be non-NULL, else we punt and return the
+	 * original array.
+	 */
+	if (sbstate->resnull)
+		return containerSource;
+
+	return jsonb_set_element(containerSource,
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 sbstate->replacevalue,
+							 sbstate->refelemtype,
+							 sbstate->replacenull);
+}
+
+/*
+ * Perform preparation for the jsonb subscripting. Since there are not any
+ * particular restrictions for this kind of subscripting, we will verify that
+ * it is not a slice operation. This function produces an expression that
+ * represents the result of extracting a single container element or the new
+ * container value with the source data inserted into the right part of the
+ * container. If you have read until this point, and will submit a meaningful
+ * review of this patch series, I'll owe you a beer at the next PGConfEU.
+ */
+
+/*
+ * Handle jsonb-type subscripting logic.
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	SubscriptRoutines *sbsroutines = (SubscriptRoutines *)
+									 palloc(sizeof(SubscriptRoutines));
+
+	sbsroutines->prepare = jsonb_subscript_prepare;
+	sbsroutines->validate = jsonb_subscript_validate;
+	sbsroutines->fetch = jsonb_subscript_fetch;
+	sbsroutines->assign = jsonb_subscript_assign;
+
+	PG_RETURN_POINTER(sbsroutines);
+}
+
+SubscriptingRef *
+jsonb_subscript_prepare(bool isAssignment, SubscriptingRef *sbsref)
+{
+	if (isAssignment)
+	{
+		sbsref->refelemtype = exprType((Node *) sbsref->refassgnexpr);
+		sbsref->refassgntype = exprType((Node *) sbsref->refassgnexpr);
+	}
+	else
+		sbsref->refelemtype = JSONBOID;
+
+	return sbsref;
+}
+
+SubscriptingRef *
+jsonb_subscript_validate(bool isAssignment, SubscriptingRef *sbsref,
+						 ParseState *pstate)
+{
+	List			   *upperIndexpr = NIL;
+	ListCell		   *l;
+
+	if (sbsref->reflowerindexpr != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("jsonb subscript does not support slices"),
+				 parser_errposition(pstate, exprLocation(
+						 ((Node *) linitial(sbsref->reflowerindexpr))))));
+
+	foreach(l, sbsref->refupperindexpr)
+	{
+		Node *subexpr = (Node *) lfirst(l);
+
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(
+						((Node *) linitial(sbsref->refupperindexpr))))));
+
+		subexpr = coerce_to_target_type(pstate,
+										subexpr, exprType(subexpr),
+										TEXTOID, -1,
+										COERCION_ASSIGNMENT,
+										COERCE_IMPLICIT_CAST,
+										-1);
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript must have text type"),
+					 parser_errposition(pstate, exprLocation(subexpr))));
+
+		upperIndexpr = lappend(upperIndexpr, subexpr);
+	}
+
+	sbsref->refupperindexpr = upperIndexpr;
+
+	return sbsref;
+}
+
 /*
  * Parse information about what elements of a jsonb document we want to iterate
  * in functions iterate_json(b)_values. This information is presented in jsonb
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 8761597e12..bf0d4ef743 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10879,6 +10879,14 @@
   proargnames => '{max_data_alignment,database_block_size,blocks_per_segment,wal_block_size,bytes_per_wal_segment,max_identifier_length,max_index_columns,max_toast_chunk_size,large_object_chunk_size,float8_pass_by_value,data_page_checksum_version}',
   prosrc => 'pg_control_init' },
 
+# type subscripting support
+{ oid => '6098',
+  descr => 'Jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler',
+  prorettype => 'internal',
+  proargtypes => 'internal',
+  prosrc => 'jsonb_subscript_handler' },
+
 { oid => '6099',
   descr => 'Array subscripting logic',
   proname => 'array_subscript_handler',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 21489a02ae..fa7e1d22a5 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -456,7 +456,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubshandler => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..6e3b75d56a 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,6 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
+extern JsonbValue *to_jsonb_worker(Datum source, Oid source_type, bool is_null);
 
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..04a146a7d0 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4567,7 +4567,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4697,6 +4697,237 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+ERROR:  subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..12541e7e50 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1172,7 +1172,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1203,6 +1203,72 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--u66dlpg6gaevsofr
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v33-0004-Subscripting-documentation.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: erthalion @ 2019-02-01 10:41 UTC (permalink / raw)

Subscripting implementation for jsonb. For the sake of code reuse, some
parts of jsonb functionality were rearranged to allow use the same
functions for jsonb_set and assign subscripting operation.

Reviewed-by: Tom Lane, Arthur Zakirov
---
 src/backend/utils/adt/jsonb.c       |  27 ++-
 src/backend/utils/adt/jsonb_util.c  |  76 ++++++-
 src/backend/utils/adt/jsonfuncs.c   | 325 ++++++++++++++++++++--------
 src/include/catalog/pg_proc.dat     |   8 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   2 +
 src/test/regress/expected/jsonb.out | 233 +++++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  68 +++++-
 8 files changed, 632 insertions(+), 110 deletions(-)

diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 1e9ca046c6..f66642def3 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -1134,23 +1134,34 @@ to_jsonb(PG_FUNCTION_ARGS)
 {
 	Datum		val = PG_GETARG_DATUM(0);
 	Oid			val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
-	JsonbInState result;
-	JsonbTypeCategory tcategory;
-	Oid			outfuncoid;
+	JsonbValue *res = to_jsonb_worker(val, val_type, false);
+	PG_RETURN_POINTER(JsonbValueToJsonb(res));
+}
 
-	if (val_type == InvalidOid)
+/*
+ * Do the actual conversion to jsonb for to_jsonb function. This logic is
+ * separated because it can be useful not only in here (e.g. we use it in
+ * jsonb subscripting)
+ */
+JsonbValue *
+to_jsonb_worker(Datum source, Oid source_type, bool is_null)
+{
+	JsonbInState		result;
+	JsonbTypeCategory	tcategory;
+	Oid					outfuncoid;
+
+	if (source_type == InvalidOid)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("could not determine input data type")));
 
-	jsonb_categorize_type(val_type,
+	jsonb_categorize_type(source_type,
 						  &tcategory, &outfuncoid);
 
 	memset(&result, 0, sizeof(JsonbInState));
 
-	datum_to_jsonb(val, false, &result, tcategory, outfuncoid, false);
-
-	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
+	datum_to_jsonb(source, is_null, &result, tcategory, outfuncoid, false);
+	return result.res;
 }
 
 /*
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 5a09d65fdc..f46a2828b3 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -21,12 +21,16 @@
 #include "common/jsonapi.h"
 #include "fmgr.h"
 #include "funcapi.h"
+#include "executor/execExpr.h"
 #include "lib/stringinfo.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
+#include "parser/parse_coerce.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/hsearch.h"
+#include "utils/fmgroids.h"
 #include "utils/json.h"
 #include "utils/jsonb.h"
 #include "utils/jsonfuncs.h"
@@ -460,18 +464,22 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
+static Datum jsonb_set_element(Datum datum, Datum *path, int path_len,
+							   Datum sourceData, Oid source_type, bool is_null);
+static Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -486,6 +494,15 @@ static void transform_string_values_object_field_start(void *state, char *fname,
 static void transform_string_values_array_element_start(void *state, bool isnull);
 static void transform_string_values_scalar(void *state, char *token, JsonTokenType tokentype);
 
+static SubscriptingRef *jsonb_subscript_prepare(bool isAssignment,
+												SubscriptingRef *sbsref);
+
+static SubscriptingRef *jsonb_subscript_validate(bool isAssignment,
+												 SubscriptingRef *sbsref,
+												 ParseState *pstate);
+static Datum jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate);
+static Datum jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate);
+
 /*
  * pg_parse_json_or_ereport
  *
@@ -1447,13 +1464,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1468,9 +1481,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+static Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	Jsonb		   *res;
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	JsonbValue		tv;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1495,7 +1527,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1511,22 +1543,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1544,7 +1579,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1554,11 +1592,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1580,9 +1622,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1593,6 +1638,32 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Datum jsonbdatum, Datum *path, int path_len,
+				  Datum sourceData, Oid source_type, bool is_null)
+{
+	Jsonb			   *jb = DatumGetJsonbP(jsonbdatum);
+	JsonbValue		   *newval,
+					   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	newval = to_jsonb_worker(sourceData, source_type, is_null);
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4152,58 +4223,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4475,7 +4494,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4633,7 +4653,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4796,7 +4817,7 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 static JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4849,11 +4870,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4870,7 +4891,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4901,7 +4922,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4924,7 +4945,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4956,7 +4977,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5004,7 +5025,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5020,7 +5041,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5031,7 +5052,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5065,12 +5086,138 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
 }
 
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	return jsonb_get_element(DatumGetJsonbP(containerSource),
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 &sbstate->resnull,
+							 false);
+}
+
+
+
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	/*
+	 * the original jsonb must be non-NULL, else we punt and return the
+	 * original array.
+	 */
+	if (sbstate->resnull)
+		return containerSource;
+
+	return jsonb_set_element(containerSource,
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 sbstate->replacevalue,
+							 sbstate->refelemtype,
+							 sbstate->replacenull);
+}
+
+/*
+ * Perform preparation for the jsonb subscripting. Since there are not any
+ * particular restrictions for this kind of subscripting, we will verify that
+ * it is not a slice operation. This function produces an expression that
+ * represents the result of extracting a single container element or the new
+ * container value with the source data inserted into the right part of the
+ * container. If you have read until this point, and will submit a meaningful
+ * review of this patch series, I'll owe you a beer at the next PGConfEU.
+ */
+
+/*
+ * Handle jsonb-type subscripting logic.
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	SubscriptRoutines *sbsroutines = (SubscriptRoutines *)
+									 palloc(sizeof(SubscriptRoutines));
+
+	sbsroutines->prepare = jsonb_subscript_prepare;
+	sbsroutines->validate = jsonb_subscript_validate;
+	sbsroutines->fetch = jsonb_subscript_fetch;
+	sbsroutines->assign = jsonb_subscript_assign;
+
+	PG_RETURN_POINTER(sbsroutines);
+}
+
+SubscriptingRef *
+jsonb_subscript_prepare(bool isAssignment, SubscriptingRef *sbsref)
+{
+	if (isAssignment)
+	{
+		sbsref->refelemtype = exprType((Node *) sbsref->refassgnexpr);
+		sbsref->refassgntype = exprType((Node *) sbsref->refassgnexpr);
+	}
+	else
+		sbsref->refelemtype = JSONBOID;
+
+	return sbsref;
+}
+
+SubscriptingRef *
+jsonb_subscript_validate(bool isAssignment, SubscriptingRef *sbsref,
+						 ParseState *pstate)
+{
+	List			   *upperIndexpr = NIL;
+	ListCell		   *l;
+
+	if (sbsref->reflowerindexpr != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("jsonb subscript does not support slices"),
+				 parser_errposition(pstate, exprLocation(
+						 ((Node *) linitial(sbsref->reflowerindexpr))))));
+
+	foreach(l, sbsref->refupperindexpr)
+	{
+		Node *subexpr = (Node *) lfirst(l);
+
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(
+						((Node *) linitial(sbsref->refupperindexpr))))));
+
+		subexpr = coerce_to_target_type(pstate,
+										subexpr, exprType(subexpr),
+										TEXTOID, -1,
+										COERCION_ASSIGNMENT,
+										COERCE_IMPLICIT_CAST,
+										-1);
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript must have text type"),
+					 parser_errposition(pstate, exprLocation(subexpr))));
+
+		upperIndexpr = lappend(upperIndexpr, subexpr);
+	}
+
+	sbsref->refupperindexpr = upperIndexpr;
+
+	return sbsref;
+}
+
 /*
  * Parse information about what elements of a jsonb document we want to iterate
  * in functions iterate_json(b)_values. This information is presented in jsonb
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 8761597e12..bf0d4ef743 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10879,6 +10879,14 @@
   proargnames => '{max_data_alignment,database_block_size,blocks_per_segment,wal_block_size,bytes_per_wal_segment,max_identifier_length,max_index_columns,max_toast_chunk_size,large_object_chunk_size,float8_pass_by_value,data_page_checksum_version}',
   prosrc => 'pg_control_init' },
 
+# type subscripting support
+{ oid => '6098',
+  descr => 'Jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler',
+  prorettype => 'internal',
+  proargtypes => 'internal',
+  prosrc => 'jsonb_subscript_handler' },
+
 { oid => '6099',
   descr => 'Array subscripting logic',
   proname => 'array_subscript_handler',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 21489a02ae..fa7e1d22a5 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -456,7 +456,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubshandler => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..6e3b75d56a 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,6 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
+extern JsonbValue *to_jsonb_worker(Datum source, Oid source_type, bool is_null);
 
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..04a146a7d0 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4567,7 +4567,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4697,6 +4697,237 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+ERROR:  subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..12541e7e50 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1172,7 +1172,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1203,6 +1203,72 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--u66dlpg6gaevsofr
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v33-0004-Subscripting-documentation.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: erthalion @ 2019-02-01 10:41 UTC (permalink / raw)

Subscripting implementation for jsonb. For the sake of code reuse, some
parts of jsonb functionality were rearranged to allow use the same
functions for jsonb_set and assign subscripting operation.

Reviewed-by: Tom Lane, Arthur Zakirov
---
 src/backend/utils/adt/jsonb.c       |  27 ++-
 src/backend/utils/adt/jsonb_util.c  |  76 ++++++-
 src/backend/utils/adt/jsonfuncs.c   | 325 ++++++++++++++++++++--------
 src/include/catalog/pg_proc.dat     |   8 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   2 +
 src/test/regress/expected/jsonb.out | 233 +++++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  68 +++++-
 8 files changed, 632 insertions(+), 110 deletions(-)

diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 1e9ca046c6..f66642def3 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -1134,23 +1134,34 @@ to_jsonb(PG_FUNCTION_ARGS)
 {
 	Datum		val = PG_GETARG_DATUM(0);
 	Oid			val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
-	JsonbInState result;
-	JsonbTypeCategory tcategory;
-	Oid			outfuncoid;
+	JsonbValue *res = to_jsonb_worker(val, val_type, false);
+	PG_RETURN_POINTER(JsonbValueToJsonb(res));
+}
 
-	if (val_type == InvalidOid)
+/*
+ * Do the actual conversion to jsonb for to_jsonb function. This logic is
+ * separated because it can be useful not only in here (e.g. we use it in
+ * jsonb subscripting)
+ */
+JsonbValue *
+to_jsonb_worker(Datum source, Oid source_type, bool is_null)
+{
+	JsonbInState		result;
+	JsonbTypeCategory	tcategory;
+	Oid					outfuncoid;
+
+	if (source_type == InvalidOid)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("could not determine input data type")));
 
-	jsonb_categorize_type(val_type,
+	jsonb_categorize_type(source_type,
 						  &tcategory, &outfuncoid);
 
 	memset(&result, 0, sizeof(JsonbInState));
 
-	datum_to_jsonb(val, false, &result, tcategory, outfuncoid, false);
-
-	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
+	datum_to_jsonb(source, is_null, &result, tcategory, outfuncoid, false);
+	return result.res;
 }
 
 /*
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 5a09d65fdc..f46a2828b3 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -21,12 +21,16 @@
 #include "common/jsonapi.h"
 #include "fmgr.h"
 #include "funcapi.h"
+#include "executor/execExpr.h"
 #include "lib/stringinfo.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
+#include "parser/parse_coerce.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/hsearch.h"
+#include "utils/fmgroids.h"
 #include "utils/json.h"
 #include "utils/jsonb.h"
 #include "utils/jsonfuncs.h"
@@ -460,18 +464,22 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
+static Datum jsonb_set_element(Datum datum, Datum *path, int path_len,
+							   Datum sourceData, Oid source_type, bool is_null);
+static Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -486,6 +494,15 @@ static void transform_string_values_object_field_start(void *state, char *fname,
 static void transform_string_values_array_element_start(void *state, bool isnull);
 static void transform_string_values_scalar(void *state, char *token, JsonTokenType tokentype);
 
+static SubscriptingRef *jsonb_subscript_prepare(bool isAssignment,
+												SubscriptingRef *sbsref);
+
+static SubscriptingRef *jsonb_subscript_validate(bool isAssignment,
+												 SubscriptingRef *sbsref,
+												 ParseState *pstate);
+static Datum jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate);
+static Datum jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate);
+
 /*
  * pg_parse_json_or_ereport
  *
@@ -1447,13 +1464,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1468,9 +1481,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+static Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	Jsonb		   *res;
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	JsonbValue		tv;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1495,7 +1527,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1511,22 +1543,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1544,7 +1579,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1554,11 +1592,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1580,9 +1622,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1593,6 +1638,32 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Datum jsonbdatum, Datum *path, int path_len,
+				  Datum sourceData, Oid source_type, bool is_null)
+{
+	Jsonb			   *jb = DatumGetJsonbP(jsonbdatum);
+	JsonbValue		   *newval,
+					   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	newval = to_jsonb_worker(sourceData, source_type, is_null);
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4152,58 +4223,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4475,7 +4494,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4633,7 +4653,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4796,7 +4817,7 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 static JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4849,11 +4870,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4870,7 +4891,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4901,7 +4922,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4924,7 +4945,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4956,7 +4977,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5004,7 +5025,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5020,7 +5041,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5031,7 +5052,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5065,12 +5086,138 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
 }
 
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	return jsonb_get_element(DatumGetJsonbP(containerSource),
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 &sbstate->resnull,
+							 false);
+}
+
+
+
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	/*
+	 * the original jsonb must be non-NULL, else we punt and return the
+	 * original array.
+	 */
+	if (sbstate->resnull)
+		return containerSource;
+
+	return jsonb_set_element(containerSource,
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 sbstate->replacevalue,
+							 sbstate->refelemtype,
+							 sbstate->replacenull);
+}
+
+/*
+ * Perform preparation for the jsonb subscripting. Since there are not any
+ * particular restrictions for this kind of subscripting, we will verify that
+ * it is not a slice operation. This function produces an expression that
+ * represents the result of extracting a single container element or the new
+ * container value with the source data inserted into the right part of the
+ * container. If you have read until this point, and will submit a meaningful
+ * review of this patch series, I'll owe you a beer at the next PGConfEU.
+ */
+
+/*
+ * Handle jsonb-type subscripting logic.
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	SubscriptRoutines *sbsroutines = (SubscriptRoutines *)
+									 palloc(sizeof(SubscriptRoutines));
+
+	sbsroutines->prepare = jsonb_subscript_prepare;
+	sbsroutines->validate = jsonb_subscript_validate;
+	sbsroutines->fetch = jsonb_subscript_fetch;
+	sbsroutines->assign = jsonb_subscript_assign;
+
+	PG_RETURN_POINTER(sbsroutines);
+}
+
+SubscriptingRef *
+jsonb_subscript_prepare(bool isAssignment, SubscriptingRef *sbsref)
+{
+	if (isAssignment)
+	{
+		sbsref->refelemtype = exprType((Node *) sbsref->refassgnexpr);
+		sbsref->refassgntype = exprType((Node *) sbsref->refassgnexpr);
+	}
+	else
+		sbsref->refelemtype = JSONBOID;
+
+	return sbsref;
+}
+
+SubscriptingRef *
+jsonb_subscript_validate(bool isAssignment, SubscriptingRef *sbsref,
+						 ParseState *pstate)
+{
+	List			   *upperIndexpr = NIL;
+	ListCell		   *l;
+
+	if (sbsref->reflowerindexpr != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("jsonb subscript does not support slices"),
+				 parser_errposition(pstate, exprLocation(
+						 ((Node *) linitial(sbsref->reflowerindexpr))))));
+
+	foreach(l, sbsref->refupperindexpr)
+	{
+		Node *subexpr = (Node *) lfirst(l);
+
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(
+						((Node *) linitial(sbsref->refupperindexpr))))));
+
+		subexpr = coerce_to_target_type(pstate,
+										subexpr, exprType(subexpr),
+										TEXTOID, -1,
+										COERCION_ASSIGNMENT,
+										COERCE_IMPLICIT_CAST,
+										-1);
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript must have text type"),
+					 parser_errposition(pstate, exprLocation(subexpr))));
+
+		upperIndexpr = lappend(upperIndexpr, subexpr);
+	}
+
+	sbsref->refupperindexpr = upperIndexpr;
+
+	return sbsref;
+}
+
 /*
  * Parse information about what elements of a jsonb document we want to iterate
  * in functions iterate_json(b)_values. This information is presented in jsonb
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 8761597e12..bf0d4ef743 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10879,6 +10879,14 @@
   proargnames => '{max_data_alignment,database_block_size,blocks_per_segment,wal_block_size,bytes_per_wal_segment,max_identifier_length,max_index_columns,max_toast_chunk_size,large_object_chunk_size,float8_pass_by_value,data_page_checksum_version}',
   prosrc => 'pg_control_init' },
 
+# type subscripting support
+{ oid => '6098',
+  descr => 'Jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler',
+  prorettype => 'internal',
+  proargtypes => 'internal',
+  prosrc => 'jsonb_subscript_handler' },
+
 { oid => '6099',
   descr => 'Array subscripting logic',
   proname => 'array_subscript_handler',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 21489a02ae..fa7e1d22a5 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -456,7 +456,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubshandler => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..6e3b75d56a 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,6 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
+extern JsonbValue *to_jsonb_worker(Datum source, Oid source_type, bool is_null);
 
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..04a146a7d0 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4567,7 +4567,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4697,6 +4697,237 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+ERROR:  subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..12541e7e50 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1172,7 +1172,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1203,6 +1203,72 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--u66dlpg6gaevsofr
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v33-0004-Subscripting-documentation.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: erthalion @ 2019-02-01 10:41 UTC (permalink / raw)

Subscripting implementation for jsonb. For the sake of code reuse, some
parts of jsonb functionality were rearranged to allow use the same
functions for jsonb_set and assign subscripting operation.

Reviewed-by: Tom Lane, Arthur Zakirov
---
 src/backend/utils/adt/jsonb.c       |  27 ++-
 src/backend/utils/adt/jsonb_util.c  |  76 ++++++-
 src/backend/utils/adt/jsonfuncs.c   | 325 ++++++++++++++++++++--------
 src/include/catalog/pg_proc.dat     |   8 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   2 +
 src/test/regress/expected/jsonb.out | 233 +++++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  68 +++++-
 8 files changed, 632 insertions(+), 110 deletions(-)

diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 1e9ca046c6..f66642def3 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -1134,23 +1134,34 @@ to_jsonb(PG_FUNCTION_ARGS)
 {
 	Datum		val = PG_GETARG_DATUM(0);
 	Oid			val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
-	JsonbInState result;
-	JsonbTypeCategory tcategory;
-	Oid			outfuncoid;
+	JsonbValue *res = to_jsonb_worker(val, val_type, false);
+	PG_RETURN_POINTER(JsonbValueToJsonb(res));
+}
 
-	if (val_type == InvalidOid)
+/*
+ * Do the actual conversion to jsonb for to_jsonb function. This logic is
+ * separated because it can be useful not only in here (e.g. we use it in
+ * jsonb subscripting)
+ */
+JsonbValue *
+to_jsonb_worker(Datum source, Oid source_type, bool is_null)
+{
+	JsonbInState		result;
+	JsonbTypeCategory	tcategory;
+	Oid					outfuncoid;
+
+	if (source_type == InvalidOid)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("could not determine input data type")));
 
-	jsonb_categorize_type(val_type,
+	jsonb_categorize_type(source_type,
 						  &tcategory, &outfuncoid);
 
 	memset(&result, 0, sizeof(JsonbInState));
 
-	datum_to_jsonb(val, false, &result, tcategory, outfuncoid, false);
-
-	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
+	datum_to_jsonb(source, is_null, &result, tcategory, outfuncoid, false);
+	return result.res;
 }
 
 /*
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 5a09d65fdc..f46a2828b3 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -21,12 +21,16 @@
 #include "common/jsonapi.h"
 #include "fmgr.h"
 #include "funcapi.h"
+#include "executor/execExpr.h"
 #include "lib/stringinfo.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
+#include "parser/parse_coerce.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/hsearch.h"
+#include "utils/fmgroids.h"
 #include "utils/json.h"
 #include "utils/jsonb.h"
 #include "utils/jsonfuncs.h"
@@ -460,18 +464,22 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
+static Datum jsonb_set_element(Datum datum, Datum *path, int path_len,
+							   Datum sourceData, Oid source_type, bool is_null);
+static Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -486,6 +494,15 @@ static void transform_string_values_object_field_start(void *state, char *fname,
 static void transform_string_values_array_element_start(void *state, bool isnull);
 static void transform_string_values_scalar(void *state, char *token, JsonTokenType tokentype);
 
+static SubscriptingRef *jsonb_subscript_prepare(bool isAssignment,
+												SubscriptingRef *sbsref);
+
+static SubscriptingRef *jsonb_subscript_validate(bool isAssignment,
+												 SubscriptingRef *sbsref,
+												 ParseState *pstate);
+static Datum jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate);
+static Datum jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate);
+
 /*
  * pg_parse_json_or_ereport
  *
@@ -1447,13 +1464,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1468,9 +1481,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+static Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	Jsonb		   *res;
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	JsonbValue		tv;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1495,7 +1527,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1511,22 +1543,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1544,7 +1579,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1554,11 +1592,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1580,9 +1622,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1593,6 +1638,32 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Datum jsonbdatum, Datum *path, int path_len,
+				  Datum sourceData, Oid source_type, bool is_null)
+{
+	Jsonb			   *jb = DatumGetJsonbP(jsonbdatum);
+	JsonbValue		   *newval,
+					   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	newval = to_jsonb_worker(sourceData, source_type, is_null);
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4152,58 +4223,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4475,7 +4494,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4633,7 +4653,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4796,7 +4817,7 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 static JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4849,11 +4870,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4870,7 +4891,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4901,7 +4922,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4924,7 +4945,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4956,7 +4977,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5004,7 +5025,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5020,7 +5041,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5031,7 +5052,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5065,12 +5086,138 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
 }
 
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	return jsonb_get_element(DatumGetJsonbP(containerSource),
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 &sbstate->resnull,
+							 false);
+}
+
+
+
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	/*
+	 * the original jsonb must be non-NULL, else we punt and return the
+	 * original array.
+	 */
+	if (sbstate->resnull)
+		return containerSource;
+
+	return jsonb_set_element(containerSource,
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 sbstate->replacevalue,
+							 sbstate->refelemtype,
+							 sbstate->replacenull);
+}
+
+/*
+ * Perform preparation for the jsonb subscripting. Since there are not any
+ * particular restrictions for this kind of subscripting, we will verify that
+ * it is not a slice operation. This function produces an expression that
+ * represents the result of extracting a single container element or the new
+ * container value with the source data inserted into the right part of the
+ * container. If you have read until this point, and will submit a meaningful
+ * review of this patch series, I'll owe you a beer at the next PGConfEU.
+ */
+
+/*
+ * Handle jsonb-type subscripting logic.
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	SubscriptRoutines *sbsroutines = (SubscriptRoutines *)
+									 palloc(sizeof(SubscriptRoutines));
+
+	sbsroutines->prepare = jsonb_subscript_prepare;
+	sbsroutines->validate = jsonb_subscript_validate;
+	sbsroutines->fetch = jsonb_subscript_fetch;
+	sbsroutines->assign = jsonb_subscript_assign;
+
+	PG_RETURN_POINTER(sbsroutines);
+}
+
+SubscriptingRef *
+jsonb_subscript_prepare(bool isAssignment, SubscriptingRef *sbsref)
+{
+	if (isAssignment)
+	{
+		sbsref->refelemtype = exprType((Node *) sbsref->refassgnexpr);
+		sbsref->refassgntype = exprType((Node *) sbsref->refassgnexpr);
+	}
+	else
+		sbsref->refelemtype = JSONBOID;
+
+	return sbsref;
+}
+
+SubscriptingRef *
+jsonb_subscript_validate(bool isAssignment, SubscriptingRef *sbsref,
+						 ParseState *pstate)
+{
+	List			   *upperIndexpr = NIL;
+	ListCell		   *l;
+
+	if (sbsref->reflowerindexpr != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("jsonb subscript does not support slices"),
+				 parser_errposition(pstate, exprLocation(
+						 ((Node *) linitial(sbsref->reflowerindexpr))))));
+
+	foreach(l, sbsref->refupperindexpr)
+	{
+		Node *subexpr = (Node *) lfirst(l);
+
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(
+						((Node *) linitial(sbsref->refupperindexpr))))));
+
+		subexpr = coerce_to_target_type(pstate,
+										subexpr, exprType(subexpr),
+										TEXTOID, -1,
+										COERCION_ASSIGNMENT,
+										COERCE_IMPLICIT_CAST,
+										-1);
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript must have text type"),
+					 parser_errposition(pstate, exprLocation(subexpr))));
+
+		upperIndexpr = lappend(upperIndexpr, subexpr);
+	}
+
+	sbsref->refupperindexpr = upperIndexpr;
+
+	return sbsref;
+}
+
 /*
  * Parse information about what elements of a jsonb document we want to iterate
  * in functions iterate_json(b)_values. This information is presented in jsonb
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 8761597e12..bf0d4ef743 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10879,6 +10879,14 @@
   proargnames => '{max_data_alignment,database_block_size,blocks_per_segment,wal_block_size,bytes_per_wal_segment,max_identifier_length,max_index_columns,max_toast_chunk_size,large_object_chunk_size,float8_pass_by_value,data_page_checksum_version}',
   prosrc => 'pg_control_init' },
 
+# type subscripting support
+{ oid => '6098',
+  descr => 'Jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler',
+  prorettype => 'internal',
+  proargtypes => 'internal',
+  prosrc => 'jsonb_subscript_handler' },
+
 { oid => '6099',
   descr => 'Array subscripting logic',
   proname => 'array_subscript_handler',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 21489a02ae..fa7e1d22a5 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -456,7 +456,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubshandler => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..6e3b75d56a 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,6 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
+extern JsonbValue *to_jsonb_worker(Datum source, Oid source_type, bool is_null);
 
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..04a146a7d0 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4567,7 +4567,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4697,6 +4697,237 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+ERROR:  subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..12541e7e50 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1172,7 +1172,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1203,6 +1203,72 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--u66dlpg6gaevsofr
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v33-0004-Subscripting-documentation.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v33 3/5] Subscripting for jsonb
@ 2019-02-01 10:41 erthalion <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: erthalion @ 2019-02-01 10:41 UTC (permalink / raw)

Subscripting implementation for jsonb. For the sake of code reuse, some
parts of jsonb functionality were rearranged to allow use the same
functions for jsonb_set and assign subscripting operation.

Reviewed-by: Tom Lane, Arthur Zakirov
---
 src/backend/utils/adt/jsonb.c       |  27 ++-
 src/backend/utils/adt/jsonb_util.c  |  76 ++++++-
 src/backend/utils/adt/jsonfuncs.c   | 325 ++++++++++++++++++++--------
 src/include/catalog/pg_proc.dat     |   8 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   2 +
 src/test/regress/expected/jsonb.out | 233 +++++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  68 +++++-
 8 files changed, 632 insertions(+), 110 deletions(-)

diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 1e9ca046c6..f66642def3 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -1134,23 +1134,34 @@ to_jsonb(PG_FUNCTION_ARGS)
 {
 	Datum		val = PG_GETARG_DATUM(0);
 	Oid			val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
-	JsonbInState result;
-	JsonbTypeCategory tcategory;
-	Oid			outfuncoid;
+	JsonbValue *res = to_jsonb_worker(val, val_type, false);
+	PG_RETURN_POINTER(JsonbValueToJsonb(res));
+}
 
-	if (val_type == InvalidOid)
+/*
+ * Do the actual conversion to jsonb for to_jsonb function. This logic is
+ * separated because it can be useful not only in here (e.g. we use it in
+ * jsonb subscripting)
+ */
+JsonbValue *
+to_jsonb_worker(Datum source, Oid source_type, bool is_null)
+{
+	JsonbInState		result;
+	JsonbTypeCategory	tcategory;
+	Oid					outfuncoid;
+
+	if (source_type == InvalidOid)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("could not determine input data type")));
 
-	jsonb_categorize_type(val_type,
+	jsonb_categorize_type(source_type,
 						  &tcategory, &outfuncoid);
 
 	memset(&result, 0, sizeof(JsonbInState));
 
-	datum_to_jsonb(val, false, &result, tcategory, outfuncoid, false);
-
-	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
+	datum_to_jsonb(source, is_null, &result, tcategory, outfuncoid, false);
+	return result.res;
 }
 
 /*
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 5a09d65fdc..f46a2828b3 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -21,12 +21,16 @@
 #include "common/jsonapi.h"
 #include "fmgr.h"
 #include "funcapi.h"
+#include "executor/execExpr.h"
 #include "lib/stringinfo.h"
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
+#include "nodes/nodeFuncs.h"
+#include "parser/parse_coerce.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/hsearch.h"
+#include "utils/fmgroids.h"
 #include "utils/json.h"
 #include "utils/jsonb.h"
 #include "utils/jsonfuncs.h"
@@ -460,18 +464,22 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
+static Datum jsonb_set_element(Datum datum, Datum *path, int path_len,
+							   Datum sourceData, Oid source_type, bool is_null);
+static Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -486,6 +494,15 @@ static void transform_string_values_object_field_start(void *state, char *fname,
 static void transform_string_values_array_element_start(void *state, bool isnull);
 static void transform_string_values_scalar(void *state, char *token, JsonTokenType tokentype);
 
+static SubscriptingRef *jsonb_subscript_prepare(bool isAssignment,
+												SubscriptingRef *sbsref);
+
+static SubscriptingRef *jsonb_subscript_validate(bool isAssignment,
+												 SubscriptingRef *sbsref,
+												 ParseState *pstate);
+static Datum jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate);
+static Datum jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate);
+
 /*
  * pg_parse_json_or_ereport
  *
@@ -1447,13 +1464,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1468,9 +1481,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+static Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	Jsonb		   *res;
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	JsonbValue		tv;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1495,7 +1527,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1511,22 +1543,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1544,7 +1579,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1554,11 +1592,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1580,9 +1622,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1593,6 +1638,32 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Datum jsonbdatum, Datum *path, int path_len,
+				  Datum sourceData, Oid source_type, bool is_null)
+{
+	Jsonb			   *jb = DatumGetJsonbP(jsonbdatum);
+	JsonbValue		   *newval,
+					   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	newval = to_jsonb_worker(sourceData, source_type, is_null);
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4152,58 +4223,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4475,7 +4494,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4633,7 +4653,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4796,7 +4817,7 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 static JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4849,11 +4870,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4870,7 +4891,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4901,7 +4922,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4924,7 +4945,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4956,7 +4977,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5004,7 +5025,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5020,7 +5041,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5031,7 +5052,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5065,12 +5086,138 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
 }
 
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_fetch(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	return jsonb_get_element(DatumGetJsonbP(containerSource),
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 &sbstate->resnull,
+							 false);
+}
+
+
+
+/*
+ * Perform an actual data extraction or modification for the jsonb
+ * subscripting. As a result the extracted Datum or the modified containers
+ * value will be returned.
+ */
+Datum
+jsonb_subscript_assign(Datum containerSource, SubscriptingRefState *sbstate)
+{
+	/*
+	 * the original jsonb must be non-NULL, else we punt and return the
+	 * original array.
+	 */
+	if (sbstate->resnull)
+		return containerSource;
+
+	return jsonb_set_element(containerSource,
+							 sbstate->upperindex,
+							 sbstate->numupper,
+							 sbstate->replacevalue,
+							 sbstate->refelemtype,
+							 sbstate->replacenull);
+}
+
+/*
+ * Perform preparation for the jsonb subscripting. Since there are not any
+ * particular restrictions for this kind of subscripting, we will verify that
+ * it is not a slice operation. This function produces an expression that
+ * represents the result of extracting a single container element or the new
+ * container value with the source data inserted into the right part of the
+ * container. If you have read until this point, and will submit a meaningful
+ * review of this patch series, I'll owe you a beer at the next PGConfEU.
+ */
+
+/*
+ * Handle jsonb-type subscripting logic.
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	SubscriptRoutines *sbsroutines = (SubscriptRoutines *)
+									 palloc(sizeof(SubscriptRoutines));
+
+	sbsroutines->prepare = jsonb_subscript_prepare;
+	sbsroutines->validate = jsonb_subscript_validate;
+	sbsroutines->fetch = jsonb_subscript_fetch;
+	sbsroutines->assign = jsonb_subscript_assign;
+
+	PG_RETURN_POINTER(sbsroutines);
+}
+
+SubscriptingRef *
+jsonb_subscript_prepare(bool isAssignment, SubscriptingRef *sbsref)
+{
+	if (isAssignment)
+	{
+		sbsref->refelemtype = exprType((Node *) sbsref->refassgnexpr);
+		sbsref->refassgntype = exprType((Node *) sbsref->refassgnexpr);
+	}
+	else
+		sbsref->refelemtype = JSONBOID;
+
+	return sbsref;
+}
+
+SubscriptingRef *
+jsonb_subscript_validate(bool isAssignment, SubscriptingRef *sbsref,
+						 ParseState *pstate)
+{
+	List			   *upperIndexpr = NIL;
+	ListCell		   *l;
+
+	if (sbsref->reflowerindexpr != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_DATATYPE_MISMATCH),
+				 errmsg("jsonb subscript does not support slices"),
+				 parser_errposition(pstate, exprLocation(
+						 ((Node *) linitial(sbsref->reflowerindexpr))))));
+
+	foreach(l, sbsref->refupperindexpr)
+	{
+		Node *subexpr = (Node *) lfirst(l);
+
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(
+						((Node *) linitial(sbsref->refupperindexpr))))));
+
+		subexpr = coerce_to_target_type(pstate,
+										subexpr, exprType(subexpr),
+										TEXTOID, -1,
+										COERCION_ASSIGNMENT,
+										COERCE_IMPLICIT_CAST,
+										-1);
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript must have text type"),
+					 parser_errposition(pstate, exprLocation(subexpr))));
+
+		upperIndexpr = lappend(upperIndexpr, subexpr);
+	}
+
+	sbsref->refupperindexpr = upperIndexpr;
+
+	return sbsref;
+}
+
 /*
  * Parse information about what elements of a jsonb document we want to iterate
  * in functions iterate_json(b)_values. This information is presented in jsonb
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 8761597e12..bf0d4ef743 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10879,6 +10879,14 @@
   proargnames => '{max_data_alignment,database_block_size,blocks_per_segment,wal_block_size,bytes_per_wal_segment,max_identifier_length,max_index_columns,max_toast_chunk_size,large_object_chunk_size,float8_pass_by_value,data_page_checksum_version}',
   prosrc => 'pg_control_init' },
 
+# type subscripting support
+{ oid => '6098',
+  descr => 'Jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler',
+  prorettype => 'internal',
+  proargtypes => 'internal',
+  prosrc => 'jsonb_subscript_handler' },
+
 { oid => '6099',
   descr => 'Array subscripting logic',
   proname => 'array_subscript_handler',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 21489a02ae..fa7e1d22a5 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -456,7 +456,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubshandler => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..6e3b75d56a 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,6 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
+extern JsonbValue *to_jsonb_worker(Datum source, Oid source_type, bool is_null);
 
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..04a146a7d0 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4567,7 +4567,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4697,6 +4697,237 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+ERROR:  subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..12541e7e50 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1172,7 +1172,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1203,6 +1203,72 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = 1 where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = 1 where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = 'test';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = 1;
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--u66dlpg6gaevsofr
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v33-0004-Subscripting-documentation.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2v7pubbjx3p2om6u
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v45-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--mygb4tp4jvuwryfl
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v46-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2v7pubbjx3p2om6u
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v45-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--6snw7vcvuujiswgu
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v43-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--bnxkghd4qzx6dtmd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v41-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v44-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--6snw7vcvuujiswgu
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v43-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--6snw7vcvuujiswgu
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v43-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--mygb4tp4jvuwryfl
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v46-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--mygb4tp4jvuwryfl
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v46-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--6snw7vcvuujiswgu
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v43-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--3x42k255okwqcjpg
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v49-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v44-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v44-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--mygb4tp4jvuwryfl
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v46-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--m4t3wpskod5t4yye
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v48-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2lozexjxkmbehzdg
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v42-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--m4t3wpskod5t4yye
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v48-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2lozexjxkmbehzdg
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* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2lozexjxkmbehzdg
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v42-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--mygb4tp4jvuwryfl
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v46-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2lozexjxkmbehzdg
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v42-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2lozexjxkmbehzdg
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v42-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--m4t3wpskod5t4yye
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v48-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v40 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--byo64sf23gz7hdj6
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v40-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v44-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2lozexjxkmbehzdg
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v42-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--bnxkghd4qzx6dtmd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v41-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2v7pubbjx3p2om6u
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v45-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--bnxkghd4qzx6dtmd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v41-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--bnxkghd4qzx6dtmd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v41-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v44-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--m4t3wpskod5t4yye
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v48-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--6snw7vcvuujiswgu
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v43-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--6snw7vcvuujiswgu
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v43-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--bnxkghd4qzx6dtmd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v41-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2lozexjxkmbehzdg
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v42-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v49-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--mygb4tp4jvuwryfl
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v46-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--6snw7vcvuujiswgu
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v43-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2v7pubbjx3p2om6u
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v45-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2v7pubbjx3p2om6u
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v45-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v44-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2v7pubbjx3p2om6u
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v45-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2lozexjxkmbehzdg
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v42-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--6snw7vcvuujiswgu
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v43-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--m4t3wpskod5t4yye
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v48-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2lozexjxkmbehzdg
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v42-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--bnxkghd4qzx6dtmd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v41-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v44-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v44-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2lozexjxkmbehzdg
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v42-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--m4t3wpskod5t4yye
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v48-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--m4t3wpskod5t4yye
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v48-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v44-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--6snw7vcvuujiswgu
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v43-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2lozexjxkmbehzdg
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v42-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--bnxkghd4qzx6dtmd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v41-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v44-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--bnxkghd4qzx6dtmd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v41-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--6snw7vcvuujiswgu
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v43-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2v7pubbjx3p2om6u
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v45-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v44-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--m4t3wpskod5t4yye
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v48-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--m4t3wpskod5t4yye
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v48-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--m4t3wpskod5t4yye
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v48-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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Content-Disposition: attachment;
 filename="v49-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--bnxkghd4qzx6dtmd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v41-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--bnxkghd4qzx6dtmd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v41-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--mygb4tp4jvuwryfl
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v46-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2lozexjxkmbehzdg
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v42-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v44-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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 filename="v49-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--m4t3wpskod5t4yye
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v48-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2v7pubbjx3p2om6u
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v45-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v44-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--bnxkghd4qzx6dtmd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v41-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--bnxkghd4qzx6dtmd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v41-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--bnxkghd4qzx6dtmd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v41-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v44-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--bnxkghd4qzx6dtmd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v41-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--mygb4tp4jvuwryfl
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v46-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--mygb4tp4jvuwryfl
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v46-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--bnxkghd4qzx6dtmd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v41-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--mygb4tp4jvuwryfl
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v46-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--mygb4tp4jvuwryfl
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v46-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--6snw7vcvuujiswgu
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v43-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--bnxkghd4qzx6dtmd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v41-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2lozexjxkmbehzdg
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v42-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--6snw7vcvuujiswgu
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v43-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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 filename="v49-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--m4t3wpskod5t4yye
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v48-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v44-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2lozexjxkmbehzdg
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v42-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--mygb4tp4jvuwryfl
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v46-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2lozexjxkmbehzdg
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v42-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2v7pubbjx3p2om6u
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v45-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v44-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--bnxkghd4qzx6dtmd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v41-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2lozexjxkmbehzdg
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v42-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--mygb4tp4jvuwryfl
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v46-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2v7pubbjx3p2om6u
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v45-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2lozexjxkmbehzdg
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v42-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--mygb4tp4jvuwryfl
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* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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 filename="v49-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--m4t3wpskod5t4yye
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v48-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v44-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--mygb4tp4jvuwryfl
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v46-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--6snw7vcvuujiswgu
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v43-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--6snw7vcvuujiswgu
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v43-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v38] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb of type object and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 +++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 +++++++-
 src/backend/utils/adt/jsonbsubs.c   | 282 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 +++++++++---------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 273 ++++++++++++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 ++++++++-
 10 files changed, 852 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..cad7b02559 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is {"1": 1}
+UPDATE table_name SET jsonb_field[1] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index ce09ad7375..0ef0f36e36 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..b58efb7c0d
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,282 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subexpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			subexpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subexpr = coerce_to_target_type(pstate,
+											subexpr, exprType(subexpr),
+											TEXTOID, -1,
+											COERCION_ASSIGNMENT,
+											COERCE_IMPLICIT_CAST,
+											-1);
+			if (subexpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subexpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subexpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  sbsrefstate->upperindex,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb of object
+	 * type and proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+		newSource->type = jbvObject;
+		newSource->val.object.nPairs = 0;
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  sbsrefstate->upperindex,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 12557ce3af..1925cd8026 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4153,58 +4201,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4476,7 +4472,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4634,7 +4631,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4792,10 +4790,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4848,11 +4846,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4869,7 +4867,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4900,7 +4898,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4923,7 +4921,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4955,7 +4953,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5003,7 +5001,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5019,7 +5017,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5030,7 +5028,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5064,7 +5062,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index e6c7b070f6..82570cce6f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10943,6 +10943,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 28240bdce3..3c0ee2a81b 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..85f8364d70 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4567,7 +4567,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4697,6 +4697,277 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"0": 1}
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..5b8a51f712 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1172,7 +1172,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1203,6 +1203,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--hletpuqfhzttgv77--





^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v39] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 412 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 981 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index ce09ad7375..0ef0f36e36 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..b91a140494
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,412 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 12557ce3af..1925cd8026 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4153,58 +4201,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4476,7 +4472,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4634,7 +4631,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4792,10 +4790,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4848,11 +4846,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4869,7 +4867,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4900,7 +4898,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4923,7 +4921,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4955,7 +4953,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -5003,7 +5001,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5019,7 +5017,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5030,7 +5028,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5064,7 +5062,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index e6c7b070f6..82570cce6f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -10943,6 +10943,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 28240bdce3..3c0ee2a81b 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a70cd0b7c1..eefe5d55ee 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4567,7 +4567,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4697,6 +4697,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 3e2b8f66df..5b8a51f712 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1172,7 +1172,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1203,6 +1203,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--65dnqzlcwvdscbys--





^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--m4t3wpskod5t4yye
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v48-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--mygb4tp4jvuwryfl
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v46-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2v7pubbjx3p2om6u
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v45-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--6snw7vcvuujiswgu
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v43-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2v7pubbjx3p2om6u
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v45-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v44-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2lozexjxkmbehzdg
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v42-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--bnxkghd4qzx6dtmd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v41-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--mygb4tp4jvuwryfl
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v46-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--6snw7vcvuujiswgu
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v43-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--m4t3wpskod5t4yye
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v48-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--bnxkghd4qzx6dtmd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v41-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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 filename="v49-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--mygb4tp4jvuwryfl
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v46-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--6snw7vcvuujiswgu
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v43-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--6snw7vcvuujiswgu
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v43-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--bnxkghd4qzx6dtmd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v41-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--6snw7vcvuujiswgu
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v43-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--mygb4tp4jvuwryfl
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v46-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v43 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--6snw7vcvuujiswgu
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v43-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2v7pubbjx3p2om6u
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v45-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2v7pubbjx3p2om6u
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v45-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--m4t3wpskod5t4yye
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v48-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--m4t3wpskod5t4yye
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v48-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v48 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--m4t3wpskod5t4yye
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v48-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v44-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v42 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2lozexjxkmbehzdg
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v42-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--mygb4tp4jvuwryfl
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v46-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v44-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2v7pubbjx3p2om6u
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v45-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v41 1/2] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--bnxkghd4qzx6dtmd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v41-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v44 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--i5uwshohlpbxyckd
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v44-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v49 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


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^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v46 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay
---
 doc/src/sgml/json.sgml              |  51 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 985 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..3ace5e444b 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,57 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   The <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract and modify elements. Nested values can be indicated by chaining
+   subscripting expressions, following the same rules as the <literal>path</literal>
+   argument in the <literal>jsonb_set</literal> function. If a <type>jsonb</type>
+   value is an array, numeric subscripts start at zero, and negative integers count
+   backwards from the last element of the array. Slice expressions are not supported.
+   The result of a subscripting expression is always of the jsonb data type.
+  </para>
+
+  <para>
+   An example of subscripting syntax:
+<programlisting>
+
+-- Extract object value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested object value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract array element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update object value by key. Note the quotes around '1': the assigned
+-- value must be of the jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Filter records using a WHERE clause with subscripting. Since the result of
+-- subscripting is jsonb, the value we compare it against must also be jsonb.
+-- The double quotes make "value" also a valid jsonb string.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+   <type>jsonb</type> assignment via subscripting handles a few edge cases
+   differently from <literal>jsonb_set</literal>. When a source <type>jsonb</type>
+   is <literal>NULL</literal>, assignment via subscripting will proceed as if
+   it was an empty JSON object:
+
+<programlisting>
+-- Where jsonb_field was NULL, it is now {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- Where jsonb_field was NULL, it is now [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..5237414be4
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coerced to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+												   sbsrefstate->upperindex,
+												   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+						nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int		i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..46bf2e2353 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coerced to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--mygb4tp4jvuwryfl
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v46-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* [PATCH v45 1/3] Subscripting for jsonb
@ 2020-12-18 16:19 Dmitrii Dolgov <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Dmitrii Dolgov @ 2020-12-18 16:19 UTC (permalink / raw)

Subscripting implementation for jsonb. It does not support slices, does
not have a limit for number of subscripts and for assignment expects a
replace value to be of jsonb type. There is also one functional
difference in assignment via subscripting from jsonb_set, when an
original jsonb container is NULL, subscripting replaces it with an empty
jsonb and proceed with assignment.

For the sake of code reuse, some parts of jsonb functionality were
rearranged to allow use the same functions for jsonb_set and assign
subscripting operation.

The original idea belongs to Oleg Bartunov.

Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule
---
 doc/src/sgml/json.sgml              |  48 ++++
 src/backend/utils/adt/Makefile      |   1 +
 src/backend/utils/adt/jsonb_util.c  |  76 ++++-
 src/backend/utils/adt/jsonbsubs.c   | 413 ++++++++++++++++++++++++++++
 src/backend/utils/adt/jsonfuncs.c   | 180 ++++++------
 src/include/catalog/pg_proc.dat     |   4 +
 src/include/catalog/pg_type.dat     |   3 +-
 src/include/utils/jsonb.h           |   6 +-
 src/test/regress/expected/jsonb.out | 272 +++++++++++++++++-
 src/test/regress/sql/jsonb.sql      |  84 +++++-
 10 files changed, 982 insertions(+), 105 deletions(-)
 create mode 100644 src/backend/utils/adt/jsonbsubs.c

diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 5b9a5557a4..100d1a60f4 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -602,6 +602,54 @@ SELECT jdoc-&gt;'guid', jdoc-&gt;'name' FROM api WHERE jdoc @&gt; '{"tags": ["qu
   </para>
  </sect2>
 
+ <sect2 id="jsonb-subscripting">
+  <title><type>jsonb</type> Subscripting</title>
+  <para>
+   <type>jsonb</type> data type supports array-style subscripting expressions
+   to extract or update particular elements. It's possible to use multiple
+   subscripting expressions to extract nested values. In this case, a chain of
+   subscripting expressions follows the same rules as the
+   <literal>path</literal> argument in <literal>jsonb_set</literal> function,
+   e.g. in case of arrays it is a 0-based operation or that negative integers
+   that appear in <literal>path</literal> count from the end of JSON arrays.
+   The result of subscripting expressions is always jsonb data type. An
+   example of subscripting syntax:
+<programlisting>
+-- Extract value by key
+SELECT ('{"a": 1}'::jsonb)['a'];
+
+-- Extract nested value by key path
+SELECT ('{"a": {"b": {"c": 1}}}'::jsonb)['a']['b']['c'];
+
+-- Extract element by index
+SELECT ('[1, "2", null]'::jsonb)[1];
+
+-- Update value by key, note the single quotes - the assigned value
+-- needs to be of jsonb type as well
+UPDATE table_name SET jsonb_field['key'] = '1';
+
+-- Select records using where clause with subscripting. Since the result of
+-- subscripting is jsonb and we basically want to compare two jsonb objects, we
+-- need to put the value in double quotes to be able to convert it to jsonb.
+SELECT * FROM table_name WHERE jsonb_field['key'] = '"value"';
+</programlisting>
+
+  Subscripting for <type>jsonb</type> does not support slice expressions,
+  even if it contains an array.
+
+  In case if source <type>jsonb</type> is <literal>NULL</literal>, assignment
+  via subscripting will proceed as if it was an empty JSON object:
+<programlisting>
+-- If jsonb_field here is NULL, the result is {"a": 1}
+UPDATE table_name SET jsonb_field['a'] = '1';
+
+-- If jsonb_field here is NULL, the result is [1]
+UPDATE table_name SET jsonb_field[0] = '1';
+</programlisting>
+
+  </para>
+ </sect2>
+
  <sect2>
   <title>Transforms</title>
 
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 82732146d3..279ff15ade 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -50,6 +50,7 @@ OBJS = \
 	jsonb_op.o \
 	jsonb_util.o \
 	jsonfuncs.o \
+	jsonbsubs.o \
 	jsonpath.o \
 	jsonpath_exec.o \
 	jsonpath_gram.o \
diff --git a/src/backend/utils/adt/jsonb_util.c b/src/backend/utils/adt/jsonb_util.c
index 4eeffa1424..41a1c1f9bb 100644
--- a/src/backend/utils/adt/jsonb_util.c
+++ b/src/backend/utils/adt/jsonb_util.c
@@ -68,18 +68,29 @@ static JsonbValue *pushJsonbValueScalar(JsonbParseState **pstate,
 										JsonbIteratorToken seq,
 										JsonbValue *scalarVal);
 
+JsonbValue *
+JsonbToJsonbValue(Jsonb *jsonb)
+{
+	JsonbValue *val = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+	val->type = jbvBinary;
+	val->val.binary.data = &jsonb->root;
+	val->val.binary.len = VARSIZE(jsonb) - VARHDRSZ;
+
+	return val;
+}
+
 /*
  * Turn an in-memory JsonbValue into a Jsonb for on-disk storage.
  *
- * There isn't a JsonbToJsonbValue(), because generally we find it more
- * convenient to directly iterate through the Jsonb representation and only
- * really convert nested scalar values.  JsonbIteratorNext() does this, so that
- * clients of the iteration code don't have to directly deal with the binary
- * representation (JsonbDeepContains() is a notable exception, although all
- * exceptions are internal to this module).  In general, functions that accept
- * a JsonbValue argument are concerned with the manipulation of scalar values,
- * or simple containers of scalar values, where it would be inconvenient to
- * deal with a great amount of other state.
+ * Generally we find it more convenient to directly iterate through the Jsonb
+ * representation and only really convert nested scalar values.
+ * JsonbIteratorNext() does this, so that clients of the iteration code don't
+ * have to directly deal with the binary representation (JsonbDeepContains() is
+ * a notable exception, although all exceptions are internal to this module).
+ * In general, functions that accept a JsonbValue argument are concerned with
+ * the manipulation of scalar values, or simple containers of scalar values,
+ * where it would be inconvenient to deal with a great amount of other state.
  */
 Jsonb *
 JsonbValueToJsonb(JsonbValue *val)
@@ -563,6 +574,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 	JsonbValue *res = NULL;
 	JsonbValue	v;
 	JsonbIteratorToken tok;
+	int	i;
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvObject)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_OBJECT, NULL);
+		for (i = 0; i < jbval->val.object.nPairs; i++)
+		{
+			pushJsonbValue(pstate, WJB_KEY, &jbval->val.object.pairs[i].key);
+			pushJsonbValue(pstate, WJB_VALUE, &jbval->val.object.pairs[i].value);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_OBJECT, NULL);
+	}
+
+	if (jbval && (seq == WJB_ELEM || seq == WJB_VALUE) && jbval->type == jbvArray)
+	{
+		pushJsonbValue(pstate, WJB_BEGIN_ARRAY, NULL);
+		for (i = 0; i < jbval->val.array.nElems; i++)
+		{
+			pushJsonbValue(pstate, WJB_ELEM, &jbval->val.array.elems[i]);
+		}
+
+		return pushJsonbValue(pstate, WJB_END_ARRAY, NULL);
+	}
 
 	if (!jbval || (seq != WJB_ELEM && seq != WJB_VALUE) ||
 		jbval->type != jbvBinary)
@@ -573,9 +608,30 @@ pushJsonbValue(JsonbParseState **pstate, JsonbIteratorToken seq,
 
 	/* unpack the binary and add each piece to the pstate */
 	it = JsonbIteratorInit(jbval->val.binary.data);
+
+	if ((jbval->val.binary.data->header & JB_FSCALAR) && *pstate)
+	{
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_BEGIN_ARRAY);
+		Assert(v.type == jbvArray && v.val.array.rawScalar);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_ELEM);
+
+		res = pushJsonbValueScalar(pstate, seq, &v);
+
+		tok = JsonbIteratorNext(&it, &v, true);
+		Assert(tok == WJB_END_ARRAY);
+		Assert(it == NULL);
+
+		return res;
+	}
+
 	while ((tok = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
 		res = pushJsonbValueScalar(pstate, tok,
-								   tok < WJB_BEGIN_ARRAY ? &v : NULL);
+								   tok < WJB_BEGIN_ARRAY ||
+								   (tok == WJB_BEGIN_ARRAY &&
+									v.val.array.rawScalar) ? &v : NULL);
 
 	return res;
 }
diff --git a/src/backend/utils/adt/jsonbsubs.c b/src/backend/utils/adt/jsonbsubs.c
new file mode 100644
index 0000000000..306c37b5a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonbsubs.c
@@ -0,0 +1,413 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonbsubs.c
+ *	  Subscripting support functions for jsonb.
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/jsonbsubs.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "executor/execExpr.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "nodes/subscripting.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "utils/jsonb.h"
+#include "utils/jsonfuncs.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+
+
+/* SubscriptingRefState.workspace for jsonb subscripting execution */
+typedef struct JsonbSubWorkspace
+{
+	bool		expectArray;	/* jsonb root is expected to be an array */
+	Oid		   *indexOid;		/* OID of coerced subscript expression,
+								   could be only integer or text */
+	Datum	   *index;			/* Subscript values in Datum format */
+} JsonbSubWorkspace;
+
+
+/*
+ * Finish parse analysis of a SubscriptingRef expression for a jsonb.
+ *
+ * Transform the subscript expressions, coerce them to text,
+ * and determine the result type of the SubscriptingRef node.
+ */
+static void
+jsonb_subscript_transform(SubscriptingRef *sbsref,
+						  List *indirection,
+						  ParseState *pstate,
+						  bool isSlice,
+						  bool isAssignment)
+{
+	List	   *upperIndexpr = NIL;
+	ListCell   *idx;
+
+	/*
+	 * Transform and convert the subscript expressions. Jsonb subscripting does
+	 * not support slices, look only and the upper index.
+	 */
+	foreach(idx, indirection)
+	{
+		A_Indices  *ai = lfirst_node(A_Indices, idx);
+		Node	   *subExpr;
+
+		if (isSlice)
+		{
+			Node	*expr = ai->uidx ? ai->uidx : ai->lidx;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(expr))));
+		}
+
+		if (ai->uidx)
+		{
+			Oid subExprType = InvalidOid,
+				targetType = UNKNOWNOID;
+
+			subExpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+			subExprType = exprType(subExpr);
+
+			if (subExprType != UNKNOWNOID)
+			{
+				Oid 	targets[2] = {INT4OID, TEXTOID};
+
+				/*
+				 * Jsonb can handle multiple subscript types, but cases when a
+				 * subscript could be coerced to multiple target types must be
+				 * avoided, similar to overloaded functions. It could be
+				 * possibly extend with jsonpath in the future.
+				 */
+				for (int i = 0; i < 2; i++)
+				{
+					if (can_coerce_type(1, &subExprType, &targets[i], COERCION_IMPLICIT))
+					{
+						/*
+						 * One type has already succeeded, it means there are
+						 * two coercion targets possible, failure.
+						 */
+						if (targetType != UNKNOWNOID)
+							ereport(ERROR,
+									(errcode(ERRCODE_DATATYPE_MISMATCH),
+									 errmsg("subscript type is not supported"),
+									 errhint("Jsonb subscript must be coerced "
+											 "only to one type, integer or text."),
+									 parser_errposition(pstate, exprLocation(subExpr))));
+
+						targetType = targets[i];
+					}
+				}
+
+				/*
+				 * No suitable types were found, failure.
+				 */
+				if (targetType == UNKNOWNOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_DATATYPE_MISMATCH),
+							 errmsg("subscript type is not supported"),
+							 errhint("Jsonb subscript must be coercet to either integer or text"),
+							 parser_errposition(pstate, exprLocation(subExpr))));
+			}
+			else
+				targetType = TEXTOID;
+
+			/*
+			 * We known from can_coerce_type that coercion will succeed, so
+			 * coerce_type could be used. Note the implicit coercion context,
+			 * which is required to handle subscripts of different types,
+			 * similar to overloaded functions.
+			 */
+			subExpr = coerce_type(pstate,
+								  subExpr, subExprType,
+								  targetType, -1,
+								  COERCION_IMPLICIT,
+								  COERCE_IMPLICIT_CAST,
+								  -1);
+			if (subExpr == NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("jsonb subscript must have text type"),
+						 parser_errposition(pstate, exprLocation(subExpr))));
+		}
+		else
+		{
+			/*
+			 * Slice with omitted upper bound. Should not happen as we already
+			 * errored out on slice earlier, but handle this just in case.
+			 */
+			Assert(isSlice && ai->is_slice);
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("jsonb subscript does not support slices"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
+		}
+
+		upperIndexpr = lappend(upperIndexpr, subExpr);
+	}
+
+	/* store the transformed lists into the SubscriptRef node */
+	sbsref->refupperindexpr = upperIndexpr;
+	sbsref->reflowerindexpr = NIL;
+
+	/* Determine the result type of the subscripting operation; always jsonb */
+	sbsref->refrestype = JSONBOID;
+	sbsref->reftypmod = -1;
+}
+
+/*
+ * During execution, process the subscripts in a SubscriptingRef expression.
+ *
+ * The subscript expressions are already evaluated in Datum form in the
+ * SubscriptingRefState's arrays.  Check and convert them as necessary.
+ *
+ * If any subscript is NULL, we throw error in assignment cases, or in fetch
+ * cases set result to NULL and return false (instructing caller to skip the
+ * rest of the SubscriptingRef sequence).
+ */
+static bool
+jsonb_subscript_check_subscripts(ExprState *state,
+								 ExprEvalStep *op,
+								 ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref_subscript.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+
+	/*
+	 * In case if the first subscript is an integer, the source jsonb is
+	 * expected to be an array. This information is not used directly, all such
+	 * cases are handled within corresponding jsonb assign functions. But if
+	 * the source jsonb is NULL the expected type will be used to construct an
+	 * empty source.
+	 */
+	if (sbsrefstate->numupper > 0 && sbsrefstate->upperprovided[0] &&
+		!sbsrefstate->upperindexnull[0] && workspace->indexOid[0] == INT4OID)
+		workspace->expectArray = true;
+
+	/* Process upper subscripts */
+	for (int i = 0; i < sbsrefstate->numupper; i++)
+	{
+		if (sbsrefstate->upperprovided[i])
+		{
+			/* If any index expr yields NULL, result is NULL or error */
+			if (sbsrefstate->upperindexnull[i])
+			{
+				if (sbsrefstate->isassignment)
+					ereport(ERROR,
+							(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+							 errmsg("jsonb subscript in assignment must not be null")));
+				*op->resnull = true;
+				return false;
+			}
+
+			/*
+			 * For jsonb fetch and assign functions we need to provide path in
+			 * text format. Convert if it's not already text.
+			 */
+			if (workspace->indexOid[i] == INT4OID)
+			{
+				Datum	datum = sbsrefstate->upperindex[i];
+				char   *cs = DatumGetCString(DirectFunctionCall1(int4out, datum));
+				workspace->index[i] = CStringGetTextDatum(cs);
+			}
+			else
+				workspace->index[i] = sbsrefstate->upperindex[i];
+		}
+	}
+
+	return true;
+}
+
+/*
+ * Evaluate SubscriptingRef fetch for a jsonb element.
+ *
+ * Source container is in step's result variable (it's known not NULL, since
+ * we set fetch_strict to true).
+ */
+static void
+jsonb_subscript_fetch(ExprState *state,
+					  ExprEvalStep *op,
+					  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+
+	/* Should not get here if source jsonb (or any subscript) is null */
+	Assert(!(*op->resnull));
+
+	jsonbSource = DatumGetJsonbP(*op->resvalue);
+	*op->resvalue = jsonb_get_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  op->resnull,
+									  false);
+}
+
+/*
+ * Evaluate SubscriptingRef assignment for a jsonb element assignment.
+ *
+ * Input container (possibly null) is in result area, replacement value is in
+ * SubscriptingRefState's replacevalue/replacenull.
+ */
+static void
+jsonb_subscript_assign(ExprState *state,
+					   ExprEvalStep *op,
+					   ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+	JsonbSubWorkspace *workspace = (JsonbSubWorkspace *) sbsrefstate->workspace;
+	Jsonb		*jsonbSource;
+	JsonbValue	*replacevalue;
+
+	if (sbsrefstate->replacenull)
+	{
+		replacevalue = (JsonbValue *) palloc(sizeof(JsonbValue));
+		replacevalue->type = jbvNull;
+	}
+	else
+		replacevalue =
+			JsonbToJsonbValue(DatumGetJsonbP(sbsrefstate->replacevalue));
+
+	/*
+	 * In case if the input container is null, set up an empty jsonb and
+	 * proceed with the assignment.
+	 */
+	if (*op->resnull)
+	{
+		JsonbValue *newSource = (JsonbValue *) palloc(sizeof(JsonbValue));
+
+		/*
+		 * To avoid any surprising results, set up an empty jsonb array in case
+		 * of an array is expected (i.e. the first subscript is integer),
+		 * otherwise jsonb object.
+		 */
+		if (workspace->expectArray)
+		{
+			newSource->type = jbvArray;
+			newSource->val.array.nElems = 0;
+			newSource->val.array.rawScalar = false;
+		}
+		else
+		{
+			newSource->type = jbvObject;
+			newSource->val.object.nPairs = 0;
+		}
+
+		jsonbSource = JsonbValueToJsonb(newSource);
+		*op->resnull = false;
+	}
+	else
+		jsonbSource = DatumGetJsonbP(*op->resvalue);
+
+	*op->resvalue = jsonb_set_element(jsonbSource,
+									  workspace->index,
+									  sbsrefstate->numupper,
+									  replacevalue);
+	/* The result is never NULL, so no need to change *op->resnull */
+}
+
+/*
+ * Compute old jsonb element value for a SubscriptingRef assignment
+ * expression.  Will only be called if the new-value subexpression
+ * contains SubscriptingRef or FieldStore.  This is the same as the
+ * regular fetch case, except that we have to handle a null jsonb,
+ * and the value should be stored into the SubscriptingRefState's
+ * prevvalue/prevnull fields.
+ */
+static void
+jsonb_subscript_fetch_old(ExprState *state,
+						  ExprEvalStep *op,
+						  ExprContext *econtext)
+{
+	SubscriptingRefState *sbsrefstate = op->d.sbsref.state;
+
+	if (*op->resnull)
+	{
+		/* whole jsonb is null, so any element is too */
+		sbsrefstate->prevvalue = (Datum) 0;
+		sbsrefstate->prevnull = true;
+	}
+	else
+	{
+		Jsonb	*jsonbSource = DatumGetJsonbP(*op->resvalue);
+		sbsrefstate->prevvalue = jsonb_get_element(jsonbSource,
+									  			   sbsrefstate->upperindex,
+									  			   sbsrefstate->numupper,
+												   &sbsrefstate->prevnull,
+												   false);
+	}
+}
+
+/*
+ * Set up execution state for a jsonb subscript operation. Opposite to the
+ * arrays subscription, there is no limit for number of subscripts as jsonb
+ * type itself doesn't have nesting limits.
+ */
+static void
+jsonb_exec_setup(const SubscriptingRef *sbsref,
+				 SubscriptingRefState *sbsrefstate,
+				 SubscriptExecSteps *methods)
+{
+	JsonbSubWorkspace *workspace;
+	ListCell   *lc;
+	int			nupper = sbsref->refupperindexpr->length;
+	char	   *ptr;
+
+	/* Allocate type-specific workspace with space for per-subscript data */
+	workspace = palloc0(MAXALIGN(sizeof(JsonbSubWorkspace)) +
+					    nupper * (sizeof(Datum) + sizeof(Oid)));
+	workspace->expectArray = false;
+	ptr = ((char *) workspace) + MAXALIGN(sizeof(JsonbSubWorkspace));
+	workspace->indexOid = (Oid *) ptr;
+	ptr += nupper * sizeof(Oid);
+	workspace->index = (Datum *) ptr;
+
+	sbsrefstate->workspace = workspace;
+
+	/* Collect subscript data types necessary at execution time */
+	foreach(lc, sbsref->refupperindexpr)
+	{
+		Node   *expr = lfirst(lc);
+		int 	i = foreach_current_index(lc);
+
+		workspace->indexOid[i] = exprType(expr);
+	}
+
+	/*
+	 * Pass back pointers to appropriate step execution functions.
+	 */
+	methods->sbs_check_subscripts = jsonb_subscript_check_subscripts;
+	methods->sbs_fetch = jsonb_subscript_fetch;
+	methods->sbs_assign = jsonb_subscript_assign;
+	methods->sbs_fetch_old = jsonb_subscript_fetch_old;
+}
+
+/*
+ * jsonb_subscript_handler
+ *		Subscripting handler for jsonb.
+ *
+ */
+Datum
+jsonb_subscript_handler(PG_FUNCTION_ARGS)
+{
+	static const SubscriptRoutines sbsroutines = {
+		.transform = jsonb_subscript_transform,
+		.exec_setup = jsonb_exec_setup,
+		.fetch_strict = true,		/* fetch returns NULL for NULL inputs */
+		.fetch_leakproof = true,	/* fetch returns NULL for bad subscript */
+		.store_leakproof = false	/* ... but assignment throws error */
+	};
+
+	PG_RETURN_POINTER(&sbsroutines);
+}
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 69100feab7..5a0ba6b220 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -461,18 +461,18 @@ static Datum populate_domain(DomainIOData *io, Oid typid, const char *colname,
 /* functions supporting jsonb_delete, jsonb_set and jsonb_concat */
 static JsonbValue *IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
 								  JsonbParseState **state);
-static JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
+extern JsonbValue *setPath(JsonbIterator **it, Datum *path_elems,
 						   bool *path_nulls, int path_len,
-						   JsonbParseState **st, int level, Jsonb *newval,
+						   JsonbParseState **st, int level, JsonbValue *newval,
 						   int op_type);
 static void setPathObject(JsonbIterator **it, Datum *path_elems,
 						  bool *path_nulls, int path_len, JsonbParseState **st,
 						  int level,
-						  Jsonb *newval, uint32 npairs, int op_type);
+						  JsonbValue *newval, uint32 npairs, int op_type);
 static void setPathArray(JsonbIterator **it, Datum *path_elems,
 						 bool *path_nulls, int path_len, JsonbParseState **st,
-						 int level, Jsonb *newval, uint32 nelems, int op_type);
-static void addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb);
+						 int level,
+						 JsonbValue *newval, uint32 nelems, int op_type);
 
 /* function supporting iterate_json_values */
 static void iterate_values_scalar(void *state, char *token, JsonTokenType tokentype);
@@ -1448,13 +1448,9 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
 	Datum	   *pathtext;
 	bool	   *pathnulls;
+	bool		isnull;
 	int			npath;
-	int			i;
-	bool		have_object = false,
-				have_array = false;
-	JsonbValue *jbvp = NULL;
-	JsonbValue	jbvbuf;
-	JsonbContainer *container;
+	Datum		res;
 
 	/*
 	 * If the array contains any null elements, return NULL, on the grounds
@@ -1469,9 +1465,26 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	deconstruct_array(path, TEXTOID, -1, false, TYPALIGN_INT,
 					  &pathtext, &pathnulls, &npath);
 
-	/* Identify whether we have object, array, or scalar at top-level */
-	container = &jb->root;
+	res = jsonb_get_element(jb, pathtext, npath, &isnull, as_text);
 
+	if (isnull)
+		PG_RETURN_NULL();
+	else
+		PG_RETURN_DATUM(res);
+}
+
+Datum
+jsonb_get_element(Jsonb *jb, Datum *path, int npath, bool *isnull, bool as_text)
+{
+	JsonbContainer *container = &jb->root;
+	JsonbValue	   *jbvp = NULL;
+	int				i;
+	bool			have_object = false,
+					have_array = false;
+
+	*isnull = false;
+
+	/* Identify whether we have object, array, or scalar at top-level */
 	if (JB_ROOT_IS_OBJECT(jb))
 		have_object = true;
 	else if (JB_ROOT_IS_ARRAY(jb) && !JB_ROOT_IS_SCALAR(jb))
@@ -1496,7 +1509,7 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	{
 		if (as_text)
 		{
-			PG_RETURN_TEXT_P(cstring_to_text(JsonbToCString(NULL,
+			return PointerGetDatum(cstring_to_text(JsonbToCString(NULL,
 															container,
 															VARSIZE(jb))));
 		}
@@ -1512,22 +1525,25 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		if (have_object)
 		{
 			jbvp = getKeyJsonValueFromContainer(container,
-												VARDATA(pathtext[i]),
-												VARSIZE(pathtext[i]) - VARHDRSZ,
-												&jbvbuf);
+												VARDATA(path[i]),
+												VARSIZE(path[i]) - VARHDRSZ,
+												NULL);
 		}
 		else if (have_array)
 		{
 			long		lindex;
 			uint32		index;
-			char	   *indextext = TextDatumGetCString(pathtext[i]);
+			char	   *indextext = TextDatumGetCString(path[i]);
 			char	   *endptr;
 
 			errno = 0;
 			lindex = strtol(indextext, &endptr, 10);
 			if (endptr == indextext || *endptr != '\0' || errno != 0 ||
 				lindex > INT_MAX || lindex < INT_MIN)
-				PG_RETURN_NULL();
+			{
+				*isnull = true;
+				return PointerGetDatum(NULL);
+			}
 
 			if (lindex >= 0)
 			{
@@ -1545,7 +1561,10 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 				nelements = JsonContainerSize(container);
 
 				if (-lindex > nelements)
-					PG_RETURN_NULL();
+				{
+					*isnull = true;
+					return PointerGetDatum(NULL);
+				}
 				else
 					index = nelements + lindex;
 			}
@@ -1555,11 +1574,15 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 		else
 		{
 			/* scalar, extraction yields a null */
-			PG_RETURN_NULL();
+			*isnull = true;
+			return PointerGetDatum(NULL);
 		}
 
 		if (jbvp == NULL)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 		else if (i == npath - 1)
 			break;
 
@@ -1581,9 +1604,12 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	if (as_text)
 	{
 		if (jbvp->type == jbvNull)
-			PG_RETURN_NULL();
+		{
+			*isnull = true;
+			return PointerGetDatum(NULL);
+		}
 
-		PG_RETURN_TEXT_P(JsonbValueAsText(jbvp));
+		return PointerGetDatum(JsonbValueAsText(jbvp));
 	}
 	else
 	{
@@ -1594,6 +1620,28 @@ get_jsonb_path_all(FunctionCallInfo fcinfo, bool as_text)
 	}
 }
 
+Datum
+jsonb_set_element(Jsonb* jb, Datum *path, int path_len,
+				  JsonbValue *newval)
+{
+	JsonbValue		   *res;
+	JsonbParseState    *state = NULL;
+	JsonbIterator 	   *it;
+	bool			   *path_nulls = palloc0(path_len * sizeof(bool));
+
+	if (newval->type == jbvArray && newval->val.array.rawScalar)
+		*newval = newval->val.array.elems[0];
+
+	it = JsonbIteratorInit(&jb->root);
+
+	res = setPath(&it, path, path_nulls, path_len, &state, 0,
+				  newval, JB_PATH_CREATE);
+
+	pfree(path_nulls);
+
+	PG_RETURN_JSONB_P(JsonbValueToJsonb(res));
+}
+
 /*
  * Return the text representation of the given JsonbValue.
  */
@@ -4151,58 +4199,6 @@ jsonb_strip_nulls(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(res));
 }
 
-/*
- * Add values from the jsonb to the parse state.
- *
- * If the parse state container is an object, the jsonb is pushed as
- * a value, not a key.
- *
- * This needs to be done using an iterator because pushJsonbValue doesn't
- * like getting jbvBinary values, so we can't just push jb as a whole.
- */
-static void
-addJsonbToParseState(JsonbParseState **jbps, Jsonb *jb)
-{
-	JsonbIterator *it;
-	JsonbValue *o = &(*jbps)->contVal;
-	JsonbValue	v;
-	JsonbIteratorToken type;
-
-	it = JsonbIteratorInit(&jb->root);
-
-	Assert(o->type == jbvArray || o->type == jbvObject);
-
-	if (JB_ROOT_IS_SCALAR(jb))
-	{
-		(void) JsonbIteratorNext(&it, &v, false);	/* skip array header */
-		Assert(v.type == jbvArray);
-		(void) JsonbIteratorNext(&it, &v, false);	/* fetch scalar value */
-
-		switch (o->type)
-		{
-			case jbvArray:
-				(void) pushJsonbValue(jbps, WJB_ELEM, &v);
-				break;
-			case jbvObject:
-				(void) pushJsonbValue(jbps, WJB_VALUE, &v);
-				break;
-			default:
-				elog(ERROR, "unexpected parent of nested structure");
-		}
-	}
-	else
-	{
-		while ((type = JsonbIteratorNext(&it, &v, false)) != WJB_DONE)
-		{
-			if (type == WJB_KEY || type == WJB_VALUE || type == WJB_ELEM)
-				(void) pushJsonbValue(jbps, type, &v);
-			else
-				(void) pushJsonbValue(jbps, type, NULL);
-		}
-	}
-
-}
-
 /*
  * SQL function jsonb_pretty (jsonb)
  *
@@ -4474,7 +4470,8 @@ jsonb_set(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		create = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4632,7 +4629,8 @@ jsonb_insert(PG_FUNCTION_ARGS)
 {
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1);
-	Jsonb	   *newval = PG_GETARG_JSONB_P(2);
+	Jsonb	   *newjsonb = PG_GETARG_JSONB_P(2);
+	JsonbValue *newval = JsonbToJsonbValue(newjsonb);
 	bool		after = PG_GETARG_BOOL(3);
 	JsonbValue *res = NULL;
 	Datum	   *path_elems;
@@ -4787,10 +4785,10 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2,
  * All path elements before the last must already exist
  * whatever bits in op_type are set, or nothing is done.
  */
-static JsonbValue *
+JsonbValue *
 setPath(JsonbIterator **it, Datum *path_elems,
 		bool *path_nulls, int path_len,
-		JsonbParseState **st, int level, Jsonb *newval, int op_type)
+		JsonbParseState **st, int level, JsonbValue *newval, int op_type)
 {
 	JsonbValue	v;
 	JsonbIteratorToken r;
@@ -4843,11 +4841,11 @@ setPath(JsonbIterator **it, Datum *path_elems,
 static void
 setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			  int path_len, JsonbParseState **st, int level,
-			  Jsonb *newval, uint32 npairs, int op_type)
+			  JsonbValue *newval, uint32 npairs, int op_type)
 {
-	JsonbValue	v;
 	int			i;
-	JsonbValue	k;
+	JsonbValue	k,
+				v;
 	bool		done = false;
 
 	if (level >= path_len || path_nulls[level])
@@ -4864,7 +4862,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 		(void) pushJsonbValue(st, WJB_KEY, &newkey);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_VALUE, newval);
 	}
 
 	for (i = 0; i < npairs; i++)
@@ -4895,7 +4893,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				if (!(op_type & JB_PATH_DELETE))
 				{
 					(void) pushJsonbValue(st, WJB_KEY, &k);
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_VALUE, newval);
 				}
 				done = true;
 			}
@@ -4918,7 +4916,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				newkey.val.string.val = VARDATA_ANY(path_elems[level]);
 
 				(void) pushJsonbValue(st, WJB_KEY, &newkey);
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_VALUE, newval);
 			}
 
 			(void) pushJsonbValue(st, r, &k);
@@ -4950,7 +4948,7 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 static void
 setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			 int path_len, JsonbParseState **st, int level,
-			 Jsonb *newval, uint32 nelems, int op_type)
+			 JsonbValue *newval, uint32 nelems, int op_type)
 {
 	JsonbValue	v;
 	int			idx,
@@ -4998,7 +4996,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		(op_type & JB_PATH_CREATE_OR_INSERT))
 	{
 		Assert(newval != NULL);
-		addJsonbToParseState(st, newval);
+		(void) pushJsonbValue(st, WJB_ELEM, newval);
 		done = true;
 	}
 
@@ -5014,7 +5012,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 				r = JsonbIteratorNext(it, &v, true);	/* skip */
 
 				if (op_type & (JB_PATH_INSERT_BEFORE | JB_PATH_CREATE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				/*
 				 * We should keep current value only in case of
@@ -5025,7 +5023,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 					(void) pushJsonbValue(st, r, &v);
 
 				if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE))
-					addJsonbToParseState(st, newval);
+					(void) pushJsonbValue(st, WJB_ELEM, newval);
 
 				done = true;
 			}
@@ -5059,7 +5057,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 			if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done &&
 				level == path_len - 1 && i == nelems - 1)
 			{
-				addJsonbToParseState(st, newval);
+				(void) pushJsonbValue(st, WJB_ELEM, newval);
 			}
 		}
 	}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 139f4a08bd..feae8cc4b0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11239,6 +11239,10 @@
 { oid => '9256', descr => 'raw array subscripting support',
   proname => 'raw_array_subscript_handler', prorettype => 'internal',
   proargtypes => 'internal', prosrc => 'raw_array_subscript_handler' },
+# type subscripting support
+{ oid => '6098', descr => 'jsonb subscripting logic',
+  proname => 'jsonb_subscript_handler', prorettype => 'internal',
+  proargtypes => 'internal', prosrc => 'jsonb_subscript_handler' },
 
 # collation management functions
 { oid => '3445', descr => 'import collations from operating system',
diff --git a/src/include/catalog/pg_type.dat b/src/include/catalog/pg_type.dat
index 62018f063a..4a530ca907 100644
--- a/src/include/catalog/pg_type.dat
+++ b/src/include/catalog/pg_type.dat
@@ -444,7 +444,8 @@
 { oid => '3802', array_type_oid => '3807', descr => 'Binary JSON',
   typname => 'jsonb', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonb_in', typoutput => 'jsonb_out', typreceive => 'jsonb_recv',
-  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x' },
+  typsend => 'jsonb_send', typalign => 'i', typstorage => 'x',
+  typsubscript => 'jsonb_subscript_handler' },
 { oid => '4072', array_type_oid => '4073', descr => 'JSON path',
   typname => 'jsonpath', typlen => '-1', typbyval => 'f', typcategory => 'U',
   typinput => 'jsonpath_in', typoutput => 'jsonpath_out',
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index 5860011693..64f1ccbf77 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -392,6 +392,7 @@ extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);
+extern JsonbValue *JsonbToJsonbValue(Jsonb *jsonb);
 extern Jsonb *JsonbValueToJsonb(JsonbValue *val);
 extern bool JsonbDeepContains(JsonbIterator **val,
 							  JsonbIterator **mContained);
@@ -407,5 +408,8 @@ extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *jb);
 
-
+extern Datum jsonb_set_element(Jsonb *jb, Datum *path, int path_len,
+							   JsonbValue *newval);
+extern Datum jsonb_get_element(Jsonb *jb, Datum *path, int npath,
+							   bool *isnull, bool as_text);
 #endif							/* __JSONB_H__ */
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 1e6c6ef200..bb3f25ec3f 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4599,7 +4599,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_
  {"a": 1, "b": null}
 (1 row)
 
-\pset null
+\pset null ''
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          
@@ -4729,6 +4729,276 @@ HINT:  Try using the function jsonb_set to replace key value.
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 ERROR:  cannot replace existing key
 HINT:  Try using the function jsonb_set to replace key value.
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('123'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['a'];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('{"a": 1}'::jsonb)[0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)['not_exist'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1}'::jsonb)[NULL];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[0];
+ jsonb 
+-------
+ 1
+(1 row)
+
+select ('[1, "2", null]'::jsonb)['1'];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1.0];
+ERROR:  subscript type is not supported
+LINE 1: select ('[1, "2", null]'::jsonb)[1.0];
+                                         ^
+HINT:  Jsonb subscript must be coercet to either integer or text
+select ('[1, "2", null]'::jsonb)[2];
+ jsonb 
+-------
+ null
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[3];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[-2];
+ jsonb 
+-------
+ "2"
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1]['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('[1, "2", null]'::jsonb)[1][0];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+ jsonb 
+-------
+ "c"
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+   jsonb   
+-----------
+ [1, 2, 3]
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+ jsonb 
+-------
+ 2
+(1 row)
+
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+     jsonb     
+---------------
+ {"a2": "aaa"}
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+ jsonb 
+-------
+ "aaa"
+(1 row)
+
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+ jsonb 
+-------
+ 
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+         jsonb         
+-----------------------
+ ["aaa", "bbb", "ccc"]
+(1 row)
+
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+ jsonb 
+-------
+ "ccc"
+(1 row)
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('{"a": 1}'::jsonb)['a':'b'];
+                                       ^
+select ('[1, "2", null]'::jsonb)[1:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:2];
+                                           ^
+select ('[1, "2", null]'::jsonb)[:2];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[:2];
+                                          ^
+select ('[1, "2", null]'::jsonb)[1:];
+ERROR:  jsonb subscript does not support slices
+LINE 1: select ('[1, "2", null]'::jsonb)[1:];
+                                         ^
+select ('[1, "2", null]'::jsonb)[:];
+ERROR:  jsonb subscript does not support slices
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+ id |    test_json     
+----+------------------
+  2 | {"key": "value"}
+  1 | {"a": 1}
+(2 rows)
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+ id |        test_json         
+----+--------------------------
+  1 | {"a": 1}
+  2 | {"a": 1, "key": "value"}
+(2 rows)
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+ id |           test_json           
+----+-------------------------------
+  1 | {"a": "test"}
+  2 | {"a": "test", "key": "value"}
+(2 rows)
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json            
+----+---------------------------------
+  1 | {"a": {"b": 1}}
+  2 | {"a": {"b": 1}, "key": "value"}
+(2 rows)
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+ id |            test_json             
+----+----------------------------------
+  1 | {"a": [1, 2, 3]}
+  2 | {"a": [1, 2, 3], "key": "value"}
+(2 rows)
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+ id |            test_json             
+----+----------------------------------
+  2 | {"a": [1, 2, 3], "key": "value"}
+(1 row)
+
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+ id | test_json 
+----+-----------
+(0 rows)
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+ERROR:  jsonb subscript in assignment must not be null
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+(2 rows)
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+ id |                       test_json                       
+----+-------------------------------------------------------
+  1 | {"a": [1, 2, 3], "another_key": null}
+  2 | {"a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | {"a": 1}
+(3 rows)
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+ id |                           test_json                           
+----+---------------------------------------------------------------
+  1 | {"0": 1, "a": [1, 2, 3], "another_key": null}
+  2 | {"0": 1, "a": [1, 2, 3], "key": "value", "another_key": null}
+  3 | [1]
+(3 rows)
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
                                 to_tsvector                                
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index b6409767f6..20aa8fe0e2 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1177,7 +1177,7 @@ select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'retu
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
 select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
 
-\pset null
+\pset null ''
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
@@ -1208,6 +1208,88 @@ select jsonb_insert('{"a": {"b": "value"}}', '{a, c}', '"new_value"', true);
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"');
 select jsonb_insert('{"a": {"b": "value"}}', '{a, b}', '"new_value"', true);
 
+-- jsonb subscript
+select ('123'::jsonb)['a'];
+select ('123'::jsonb)[0];
+select ('123'::jsonb)[NULL];
+select ('{"a": 1}'::jsonb)['a'];
+select ('{"a": 1}'::jsonb)[0];
+select ('{"a": 1}'::jsonb)['not_exist'];
+select ('{"a": 1}'::jsonb)[NULL];
+select ('[1, "2", null]'::jsonb)['a'];
+select ('[1, "2", null]'::jsonb)[0];
+select ('[1, "2", null]'::jsonb)['1'];
+select ('[1, "2", null]'::jsonb)[1.0];
+select ('[1, "2", null]'::jsonb)[2];
+select ('[1, "2", null]'::jsonb)[3];
+select ('[1, "2", null]'::jsonb)[-2];
+select ('[1, "2", null]'::jsonb)[1]['a'];
+select ('[1, "2", null]'::jsonb)[1][0];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['b'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d'][1];
+select ('{"a": 1, "b": "c", "d": [1, 2, 3]}'::jsonb)['d']['a'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2'];
+select ('{"a": {"a1": {"a2": "aaa"}}, "b": "bbb", "c": "ccc"}'::jsonb)['a']['a1']['a2']['a3'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'];
+select ('{"a": ["a1", {"b1": ["aaa", "bbb", "ccc"]}], "b": "bb"}'::jsonb)['a'][1]['b1'][2];
+
+-- slices are not supported
+select ('{"a": 1}'::jsonb)['a':'b'];
+select ('[1, "2", null]'::jsonb)[1:2];
+select ('[1, "2", null]'::jsonb)[:2];
+select ('[1, "2", null]'::jsonb)[1:];
+select ('[1, "2", null]'::jsonb)[:];
+
+create TEMP TABLE test_jsonb_subscript (
+       id int,
+       test_json jsonb
+);
+
+insert into test_jsonb_subscript values
+(1, '{}'), -- empty jsonb
+(2, '{"key": "value"}'); -- jsonb with data
+
+-- update empty jsonb
+update test_jsonb_subscript set test_json['a'] = '1' where id = 1;
+select * from test_jsonb_subscript;
+
+-- update jsonb with some data
+update test_jsonb_subscript set test_json['a'] = '1' where id = 2;
+select * from test_jsonb_subscript;
+
+-- replace jsonb
+update test_jsonb_subscript set test_json['a'] = '"test"';
+select * from test_jsonb_subscript;
+
+-- replace by object
+update test_jsonb_subscript set test_json['a'] = '{"b": 1}'::jsonb;
+select * from test_jsonb_subscript;
+
+-- replace by array
+update test_jsonb_subscript set test_json['a'] = '[1, 2, 3]'::jsonb;
+select * from test_jsonb_subscript;
+
+-- use jsonb subscription in where clause
+select * from test_jsonb_subscript where test_json['key'] = '"value"';
+select * from test_jsonb_subscript where test_json['key_doesnt_exists'] = '"value"';
+select * from test_jsonb_subscript where test_json['key'] = '"wrong_value"';
+
+-- NULL
+update test_jsonb_subscript set test_json[NULL] = '1';
+update test_jsonb_subscript set test_json['another_key'] = NULL;
+select * from test_jsonb_subscript;
+
+-- NULL as jsonb source
+insert into test_jsonb_subscript values (3, NULL);
+update test_jsonb_subscript set test_json['a'] = '1' where id = 3;
+select * from test_jsonb_subscript;
+
+update test_jsonb_subscript set test_json = NULL where id = 3;
+update test_jsonb_subscript set test_json[0] = '1';
+select * from test_jsonb_subscript;
+
 -- jsonb to tsvector
 select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb);
 
-- 
2.21.0


--2v7pubbjx3p2om6u
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v45-0002-Filling-gaps-in-jsonb.patch"



^ permalink  raw  reply  [nested|flat] 200+ messages in thread

* Virtual generated columns
@ 2024-04-29 08:23 Peter Eisentraut <[email protected]>
  0 siblings, 0 replies; 200+ messages in thread

From: Peter Eisentraut @ 2024-04-29 08:23 UTC (permalink / raw)
  To: pgsql-hackers

Here is a patch set to implement virtual generated columns.

Some history first:  The original development of generated columns was 
discussed in [0].  It started with virtual columns, then added stored 
columns.  Before the release of PG12, it was decided that only stored 
columns were ready, so I cut out virtual columns, and stored generated 
columns shipped with PG12, which is where we are today.

Virtual generated columns are occasionally requested still, and it's a 
bit of unfinished business for me, too, so I started to resurrect it. 
What I did here first was to basically reverse interdiff the patches 
where I cut out virtual generated columns above (this was between 
patches v8 and v9 in [0]) and clean that up and make it work again.

One thing that I needed to decide was how to organize the tests for 
this.  The original patch series had both stored and virtual tests in 
the same test file src/test/regress/sql/generated.sql.  As that file has 
grown, I think it would have been a mess to weave another whole set of 
tests into that.  So instead I figured I'd make two separate test files

     src/test/regress/sql/generated_stored.sql (renamed from current)
     src/test/regress/sql/generated_virtual.sql

and kind of try to keep them aligned, similar to how the various 
collate* tests are handled.  So I put that renaming in as preparatory 
patches.  And there are also some other preparatory cleanup patches that 
I'm including.

The main feature patch (0005 here) generally works but has a number of 
open corner cases that need to be thought about and/or fixed, many of 
which are marked in the code or the tests.  I'll continue working on 
that.  But I wanted to see if I can get some feedback on the test 
structure, so I don't have to keep changing it around later.


[0]: 
https://www.postgresql.org/message-id/flat/[email protected]
From 287a20948056b42884b4ee0f5835f1b618ae2ed7 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <[email protected]>
Date: Mon, 29 Apr 2024 09:46:43 +0200
Subject: [PATCH v0 1/5] Rename regress test generated to generated_stored

This makes naming room to have another test file for virtual generated
columns.
---
 .../regress/expected/{generated.out => generated_stored.out}    | 0
 src/test/regress/parallel_schedule                              | 2 +-
 src/test/regress/sql/{generated.sql => generated_stored.sql}    | 0
 3 files changed, 1 insertion(+), 1 deletion(-)
 rename src/test/regress/expected/{generated.out => generated_stored.out} (100%)
 rename src/test/regress/sql/{generated.sql => generated_stored.sql} (100%)

diff --git a/src/test/regress/expected/generated.out b/src/test/regress/expected/generated_stored.out
similarity index 100%
rename from src/test/regress/expected/generated.out
rename to src/test/regress/expected/generated_stored.out
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index 675c5676171..f345d6b45aa 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -66,7 +66,7 @@ test: select_into select_distinct select_distinct_on select_implicit select_havi
 # ----------
 # Another group of parallel tests
 # ----------
-test: brin gin gist spgist privileges init_privs security_label collate matview lock replica_identity rowsecurity object_address tablesample groupingsets drop_operator password identity generated join_hash
+test: brin gin gist spgist privileges init_privs security_label collate matview lock replica_identity rowsecurity object_address tablesample groupingsets drop_operator password identity generated_stored join_hash
 
 # ----------
 # Additional BRIN tests
diff --git a/src/test/regress/sql/generated.sql b/src/test/regress/sql/generated_stored.sql
similarity index 100%
rename from src/test/regress/sql/generated.sql
rename to src/test/regress/sql/generated_stored.sql

base-commit: 5c9f35fc48ea99e59300a267e090e3eafd1b3b0e
-- 
2.44.0


From 9acecbb3f45fa45522e8a4d2f10c29819d3abf54 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <[email protected]>
Date: Mon, 29 Apr 2024 09:46:43 +0200
Subject: [PATCH v0 2/5] Put generated_stored test objects in a schema

This avoids naming conflicts with concurrent tests with similarly
named objects.  Currently, there are none, but a tests for virtual
generated columns are planned to be added.
---
 .../regress/expected/generated_stored.out     | 71 ++++++++++---------
 src/test/regress/sql/generated_stored.sql     |  8 ++-
 2 files changed, 43 insertions(+), 36 deletions(-)

diff --git a/src/test/regress/expected/generated_stored.out b/src/test/regress/expected/generated_stored.out
index a4f37736623..6682092124c 100644
--- a/src/test/regress/expected/generated_stored.out
+++ b/src/test/regress/expected/generated_stored.out
@@ -4,9 +4,12 @@ SELECT attrelid, attname, attgenerated FROM pg_attribute WHERE attgenerated NOT
 ----------+---------+--------------
 (0 rows)
 
+CREATE SCHEMA generated_stored_tests;
+GRANT USAGE ON SCHEMA generated_stored_tests TO PUBLIC;
+SET search_path = generated_stored_tests;
 CREATE TABLE gtest0 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (55) STORED);
 CREATE TABLE gtest1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED);
-SELECT table_name, column_name, column_default, is_nullable, is_generated, generation_expression FROM information_schema.columns WHERE table_name LIKE 'gtest_' ORDER BY 1, 2;
+SELECT table_name, column_name, column_default, is_nullable, is_generated, generation_expression FROM information_schema.columns WHERE table_schema = 'generated_stored_tests' ORDER BY 1, 2;
  table_name | column_name | column_default | is_nullable | is_generated | generation_expression 
 ------------+-------------+----------------+-------------+--------------+-----------------------
  gtest0     | a           |                | NO          | NEVER        | 
@@ -15,14 +18,14 @@ SELECT table_name, column_name, column_default, is_nullable, is_generated, gener
  gtest1     | b           |                | YES         | ALWAYS       | (a * 2)
 (4 rows)
 
-SELECT table_name, column_name, dependent_column FROM information_schema.column_column_usage ORDER BY 1, 2, 3;
+SELECT table_name, column_name, dependent_column FROM information_schema.column_column_usage WHERE table_schema = 'generated_stored_tests' ORDER BY 1, 2, 3;
  table_name | column_name | dependent_column 
 ------------+-------------+------------------
  gtest1     | a           | b
 (1 row)
 
 \d gtest1
-                            Table "public.gtest1"
+                    Table "generated_stored_tests.gtest1"
  Column |  Type   | Collation | Nullable |              Default               
 --------+---------+-----------+----------+------------------------------------
  a      | integer |           | not null | 
@@ -270,7 +273,7 @@ SELECT * FROM gtest1_1;
 (0 rows)
 
 \d gtest1_1
-                           Table "public.gtest1_1"
+                   Table "generated_stored_tests.gtest1_1"
  Column |  Type   | Collation | Nullable |              Default               
 --------+---------+-----------+----------+------------------------------------
  a      | integer |           | not null | 
@@ -312,7 +315,7 @@ ERROR:  column "b" inherits from generated column but specifies identity
 CREATE TABLE gtestx (x int, b int GENERATED ALWAYS AS (a * 22) STORED) INHERITS (gtest1);  -- ok, overrides parent
 NOTICE:  merging column "b" with inherited definition
 \d+ gtestx
-                                                Table "public.gtestx"
+                                        Table "generated_stored_tests.gtestx"
  Column |  Type   | Collation | Nullable |               Default               | Storage | Stats target | Description 
 --------+---------+-----------+----------+-------------------------------------+---------+--------------+-------------
  a      | integer |           | not null |                                     | plain   |              | 
@@ -350,7 +353,7 @@ NOTICE:  merging multiple inherited definitions of column "b"
 NOTICE:  moving and merging column "b" with inherited definition
 DETAIL:  User-specified column moved to the position of the inherited column.
 \d gtest1_y
-                           Table "public.gtest1_y"
+                   Table "generated_stored_tests.gtest1_y"
  Column |  Type   | Collation | Nullable |              Default               
 --------+---------+-----------+----------+------------------------------------
  a      | integer |           | not null | 
@@ -525,7 +528,7 @@ HINT:  Use DROP ... CASCADE to drop the dependent objects too.
 ALTER TABLE gtest10 DROP COLUMN b CASCADE;  -- drops c too
 NOTICE:  drop cascades to column c of table gtest10
 \d gtest10
-              Table "public.gtest10"
+      Table "generated_stored_tests.gtest10"
  Column |  Type   | Collation | Nullable | Default 
 --------+---------+-----------+----------+---------
  a      | integer |           | not null | 
@@ -624,7 +627,7 @@ CREATE INDEX gtest22c_b_idx ON gtest22c (b);
 CREATE INDEX gtest22c_expr_idx ON gtest22c ((b * 3));
 CREATE INDEX gtest22c_pred_idx ON gtest22c (a) WHERE b > 0;
 \d gtest22c
-                           Table "public.gtest22c"
+                   Table "generated_stored_tests.gtest22c"
  Column |  Type   | Collation | Nullable |              Default               
 --------+---------+-----------+----------+------------------------------------
  a      | integer |           |          | 
@@ -728,7 +731,7 @@ CREATE TABLE gtest23x (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STOR
 ERROR:  invalid ON DELETE action for foreign key constraint containing generated column
 CREATE TABLE gtest23b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED REFERENCES gtest23a (x));
 \d gtest23b
-                           Table "public.gtest23b"
+                   Table "generated_stored_tests.gtest23b"
  Column |  Type   | Collation | Nullable |              Default               
 --------+---------+-----------+----------+------------------------------------
  a      | integer |           | not null | 
@@ -807,7 +810,7 @@ DROP TABLE gtest_child3;
 CREATE TABLE gtest_child3 (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 33) STORED);
 ALTER TABLE gtest_parent ATTACH PARTITION gtest_child3 FOR VALUES FROM ('2016-09-01') TO ('2016-10-01');
 \d gtest_child
-                          Table "public.gtest_child"
+                  Table "generated_stored_tests.gtest_child"
  Column |  Type  | Collation | Nullable |               Default               
 --------+--------+-----------+----------+-------------------------------------
  f1     | date   |           | not null | 
@@ -816,7 +819,7 @@ ALTER TABLE gtest_parent ATTACH PARTITION gtest_child3 FOR VALUES FROM ('2016-09
 Partition of: gtest_parent FOR VALUES FROM ('07-01-2016') TO ('08-01-2016')
 
 \d gtest_child2
-                          Table "public.gtest_child2"
+                  Table "generated_stored_tests.gtest_child2"
  Column |  Type  | Collation | Nullable |               Default                
 --------+--------+-----------+----------+--------------------------------------
  f1     | date   |           | not null | 
@@ -825,7 +828,7 @@ Partition of: gtest_parent FOR VALUES FROM ('07-01-2016') TO ('08-01-2016')
 Partition of: gtest_parent FOR VALUES FROM ('08-01-2016') TO ('09-01-2016')
 
 \d gtest_child3
-                          Table "public.gtest_child3"
+                  Table "generated_stored_tests.gtest_child3"
  Column |  Type  | Collation | Nullable |               Default                
 --------+--------+-----------+----------+--------------------------------------
  f1     | date   |           | not null | 
@@ -857,7 +860,7 @@ SELECT tableoid::regclass, * FROM gtest_parent ORDER BY 1, 2, 3;
 ALTER TABLE ONLY gtest_parent ALTER COLUMN f3 SET EXPRESSION AS (f2 * 4);
 ALTER TABLE gtest_child ALTER COLUMN f3 SET EXPRESSION AS (f2 * 10);
 \d gtest_parent
-                   Partitioned table "public.gtest_parent"
+           Partitioned table "generated_stored_tests.gtest_parent"
  Column |  Type  | Collation | Nullable |               Default               
 --------+--------+-----------+----------+-------------------------------------
  f1     | date   |           | not null | 
@@ -867,7 +870,7 @@ Partition key: RANGE (f1)
 Number of partitions: 3 (Use \d+ to list them.)
 
 \d gtest_child
-                          Table "public.gtest_child"
+                  Table "generated_stored_tests.gtest_child"
  Column |  Type  | Collation | Nullable |               Default                
 --------+--------+-----------+----------+--------------------------------------
  f1     | date   |           | not null | 
@@ -876,7 +879,7 @@ Number of partitions: 3 (Use \d+ to list them.)
 Partition of: gtest_parent FOR VALUES FROM ('07-01-2016') TO ('08-01-2016')
 
 \d gtest_child2
-                          Table "public.gtest_child2"
+                  Table "generated_stored_tests.gtest_child2"
  Column |  Type  | Collation | Nullable |               Default                
 --------+--------+-----------+----------+--------------------------------------
  f1     | date   |           | not null | 
@@ -885,7 +888,7 @@ Partition of: gtest_parent FOR VALUES FROM ('07-01-2016') TO ('08-01-2016')
 Partition of: gtest_parent FOR VALUES FROM ('08-01-2016') TO ('09-01-2016')
 
 \d gtest_child3
-                          Table "public.gtest_child3"
+                  Table "generated_stored_tests.gtest_child3"
  Column |  Type  | Collation | Nullable |               Default                
 --------+--------+-----------+----------+--------------------------------------
  f1     | date   |           | not null | 
@@ -904,7 +907,7 @@ SELECT tableoid::regclass, * FROM gtest_parent ORDER BY 1, 2, 3;
 -- alter generation expression of parent and all its children altogether
 ALTER TABLE gtest_parent ALTER COLUMN f3 SET EXPRESSION AS (f2 * 2);
 \d gtest_parent
-                   Partitioned table "public.gtest_parent"
+           Partitioned table "generated_stored_tests.gtest_parent"
  Column |  Type  | Collation | Nullable |               Default               
 --------+--------+-----------+----------+-------------------------------------
  f1     | date   |           | not null | 
@@ -914,7 +917,7 @@ Partition key: RANGE (f1)
 Number of partitions: 3 (Use \d+ to list them.)
 
 \d gtest_child
-                          Table "public.gtest_child"
+                  Table "generated_stored_tests.gtest_child"
  Column |  Type  | Collation | Nullable |               Default               
 --------+--------+-----------+----------+-------------------------------------
  f1     | date   |           | not null | 
@@ -923,7 +926,7 @@ Number of partitions: 3 (Use \d+ to list them.)
 Partition of: gtest_parent FOR VALUES FROM ('07-01-2016') TO ('08-01-2016')
 
 \d gtest_child2
-                         Table "public.gtest_child2"
+                 Table "generated_stored_tests.gtest_child2"
  Column |  Type  | Collation | Nullable |               Default               
 --------+--------+-----------+----------+-------------------------------------
  f1     | date   |           | not null | 
@@ -932,7 +935,7 @@ Partition of: gtest_parent FOR VALUES FROM ('07-01-2016') TO ('08-01-2016')
 Partition of: gtest_parent FOR VALUES FROM ('08-01-2016') TO ('09-01-2016')
 
 \d gtest_child3
-                         Table "public.gtest_child3"
+                 Table "generated_stored_tests.gtest_child3"
  Column |  Type  | Collation | Nullable |               Default               
 --------+--------+-----------+----------+-------------------------------------
  f1     | date   |           | not null | 
@@ -989,7 +992,7 @@ SELECT * FROM gtest25 ORDER BY a;
 (2 rows)
 
 \d gtest25
-                                         Table "public.gtest25"
+                                 Table "generated_stored_tests.gtest25"
  Column |       Type       | Collation | Nullable |                       Default                        
 --------+------------------+-----------+----------+------------------------------------------------------
  a      | integer          |           | not null | 
@@ -1013,7 +1016,7 @@ ERROR:  cannot alter type of a column used by a generated column
 DETAIL:  Column "a" is used by generated column "x".
 ALTER TABLE gtest27 ALTER COLUMN x TYPE numeric;
 \d gtest27
-                                Table "public.gtest27"
+                        Table "generated_stored_tests.gtest27"
  Column |  Type   | Collation | Nullable |                  Default                   
 --------+---------+-----------+----------+--------------------------------------------
  a      | integer |           |          | 
@@ -1039,7 +1042,7 @@ ALTER TABLE gtest27
   ALTER COLUMN b TYPE bigint,
   ADD COLUMN x bigint GENERATED ALWAYS AS ((a + b) * 2) STORED;
 \d gtest27
-                              Table "public.gtest27"
+                      Table "generated_stored_tests.gtest27"
  Column |  Type  | Collation | Nullable |                 Default                  
 --------+--------+-----------+----------+------------------------------------------
  a      | bigint |           |          | 
@@ -1053,7 +1056,7 @@ ALTER TABLE gtest27
 ERROR:  cannot alter type of a column used by a generated column
 DETAIL:  Column "a" is used by generated column "x".
 \d gtest27
-                              Table "public.gtest27"
+                      Table "generated_stored_tests.gtest27"
  Column |  Type  | Collation | Nullable |                 Default                  
 --------+--------+-----------+----------+------------------------------------------
  a      | bigint |           |          | 
@@ -1081,7 +1084,7 @@ SELECT * FROM gtest29;
 (2 rows)
 
 \d gtest29
-                            Table "public.gtest29"
+                    Table "generated_stored_tests.gtest29"
  Column |  Type   | Collation | Nullable |              Default               
 --------+---------+-----------+----------+------------------------------------
  a      | integer |           |          | 
@@ -1103,7 +1106,7 @@ SELECT * FROM gtest29;
 (2 rows)
 
 \d gtest29
-                            Table "public.gtest29"
+                    Table "generated_stored_tests.gtest29"
  Column |  Type   | Collation | Nullable |              Default               
 --------+---------+-----------+----------+------------------------------------
  a      | integer |           |          | 
@@ -1122,7 +1125,7 @@ SELECT * FROM gtest29;
 (4 rows)
 
 \d gtest29
-              Table "public.gtest29"
+      Table "generated_stored_tests.gtest29"
  Column |  Type   | Collation | Nullable | Default 
 --------+---------+-----------+----------+---------
  a      | integer |           |          | 
@@ -1131,7 +1134,7 @@ SELECT * FROM gtest29;
 -- check that dependencies between columns have also been removed
 ALTER TABLE gtest29 DROP COLUMN a;  -- should not drop b
 \d gtest29
-              Table "public.gtest29"
+      Table "generated_stored_tests.gtest29"
  Column |  Type   | Collation | Nullable | Default 
 --------+---------+-----------+----------+---------
  b      | integer |           |          | 
@@ -1144,7 +1147,7 @@ CREATE TABLE gtest30 (
 CREATE TABLE gtest30_1 () INHERITS (gtest30);
 ALTER TABLE gtest30 ALTER COLUMN b DROP EXPRESSION;
 \d gtest30
-              Table "public.gtest30"
+      Table "generated_stored_tests.gtest30"
  Column |  Type   | Collation | Nullable | Default 
 --------+---------+-----------+----------+---------
  a      | integer |           |          | 
@@ -1152,7 +1155,7 @@ ALTER TABLE gtest30 ALTER COLUMN b DROP EXPRESSION;
 Number of child tables: 1 (Use \d+ to list them.)
 
 \d gtest30_1
-             Table "public.gtest30_1"
+     Table "generated_stored_tests.gtest30_1"
  Column |  Type   | Collation | Nullable | Default 
 --------+---------+-----------+----------+---------
  a      | integer |           |          | 
@@ -1169,7 +1172,7 @@ CREATE TABLE gtest30_1 () INHERITS (gtest30);
 ALTER TABLE ONLY gtest30 ALTER COLUMN b DROP EXPRESSION;  -- error
 ERROR:  ALTER TABLE / DROP EXPRESSION must be applied to child tables too
 \d gtest30
-                            Table "public.gtest30"
+                    Table "generated_stored_tests.gtest30"
  Column |  Type   | Collation | Nullable |              Default               
 --------+---------+-----------+----------+------------------------------------
  a      | integer |           |          | 
@@ -1177,7 +1180,7 @@ ERROR:  ALTER TABLE / DROP EXPRESSION must be applied to child tables too
 Number of child tables: 1 (Use \d+ to list them.)
 
 \d gtest30_1
-                           Table "public.gtest30_1"
+                   Table "generated_stored_tests.gtest30_1"
  Column |  Type   | Collation | Nullable |              Default               
 --------+---------+-----------+----------+------------------------------------
  a      | integer |           |          | 
@@ -1338,14 +1341,14 @@ CREATE TABLE gtest28a (
 ALTER TABLE gtest28a DROP COLUMN a;
 CREATE TABLE gtest28b (LIKE gtest28a INCLUDING GENERATED);
 \d gtest28*
-                           Table "public.gtest28a"
+                   Table "generated_stored_tests.gtest28a"
  Column |  Type   | Collation | Nullable |              Default               
 --------+---------+-----------+----------+------------------------------------
  b      | integer |           |          | 
  c      | integer |           |          | 
  x      | integer |           |          | generated always as (b * 2) stored
 
-                           Table "public.gtest28b"
+                   Table "generated_stored_tests.gtest28b"
  Column |  Type   | Collation | Nullable |              Default               
 --------+---------+-----------+----------+------------------------------------
  b      | integer |           |          | 
diff --git a/src/test/regress/sql/generated_stored.sql b/src/test/regress/sql/generated_stored.sql
index cb55d77821f..c18e0e1f655 100644
--- a/src/test/regress/sql/generated_stored.sql
+++ b/src/test/regress/sql/generated_stored.sql
@@ -2,12 +2,16 @@
 SELECT attrelid, attname, attgenerated FROM pg_attribute WHERE attgenerated NOT IN ('', 's');
 
 
+CREATE SCHEMA generated_stored_tests;
+GRANT USAGE ON SCHEMA generated_stored_tests TO PUBLIC;
+SET search_path = generated_stored_tests;
+
 CREATE TABLE gtest0 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (55) STORED);
 CREATE TABLE gtest1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED);
 
-SELECT table_name, column_name, column_default, is_nullable, is_generated, generation_expression FROM information_schema.columns WHERE table_name LIKE 'gtest_' ORDER BY 1, 2;
+SELECT table_name, column_name, column_default, is_nullable, is_generated, generation_expression FROM information_schema.columns WHERE table_schema = 'generated_stored_tests' ORDER BY 1, 2;
 
-SELECT table_name, column_name, dependent_column FROM information_schema.column_column_usage ORDER BY 1, 2, 3;
+SELECT table_name, column_name, dependent_column FROM information_schema.column_column_usage WHERE table_schema = 'generated_stored_tests' ORDER BY 1, 2, 3;
 
 \d gtest1
 
-- 
2.44.0


From 037ca235379e7d1ca47af3b3f980cb21d22ab061 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <[email protected]>
Date: Mon, 29 Apr 2024 09:46:43 +0200
Subject: [PATCH v0 3/5] Remove useless initializations

The struct is already initialized to all zeros right before this, and
randomly initializing a few but not all fields to zero again has no
technical or educational value.
---
 src/backend/utils/cache/relcache.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index 262c9878dd3..05c4ae79707 100644
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -535,8 +535,6 @@ RelationBuildTupleDesc(Relation relation)
 
 	constr = (TupleConstr *) MemoryContextAllocZero(CacheMemoryContext,
 													sizeof(TupleConstr));
-	constr->has_not_null = false;
-	constr->has_generated_stored = false;
 
 	/*
 	 * Form a scan key that selects only user attributes (attnum > 0).
-- 
2.44.0


From 35d42f2fea33254b9c860ed54b5647728dd508ba Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <[email protected]>
Date: Mon, 29 Apr 2024 09:46:44 +0200
Subject: [PATCH v0 4/5] Remove useless code

BuildDescForRelation() goes out of its way to fill in
->constr->has_not_null, but that value is not used for anything later,
so this code can all be removed.  Note that BuildDescForRelation()
doesn't make any effort to fill in the rest of ->constr, so there is
no claim that that structure is completely filled in.
---
 src/backend/commands/tablecmds.c | 25 +++----------------------
 1 file changed, 3 insertions(+), 22 deletions(-)

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index f1725c9da8c..4ec600e21d1 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -1302,7 +1302,9 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId,
  *
  * Given a list of ColumnDef nodes, build a TupleDesc.
  *
- * Note: tdtypeid will need to be filled in later on.
+ * Note: This is only for the limited purpose of table and view creation.  Not
+ * everything is filled in.  A real tuple descriptor should be obtained from
+ * the relcache.
  */
 TupleDesc
 BuildDescForRelation(const List *columns)
@@ -1311,7 +1313,6 @@ BuildDescForRelation(const List *columns)
 	AttrNumber	attnum;
 	ListCell   *l;
 	TupleDesc	desc;
-	bool		has_not_null;
 	char	   *attname;
 	Oid			atttypid;
 	int32		atttypmod;
@@ -1323,7 +1324,6 @@ BuildDescForRelation(const List *columns)
 	 */
 	natts = list_length(columns);
 	desc = CreateTemplateTupleDesc(natts);
-	has_not_null = false;
 
 	attnum = 0;
 
@@ -1369,7 +1369,6 @@ BuildDescForRelation(const List *columns)
 
 		/* Fill in additional stuff not handled by TupleDescInitEntry */
 		att->attnotnull = entry->is_not_null;
-		has_not_null |= entry->is_not_null;
 		att->attislocal = entry->is_local;
 		att->attinhcount = entry->inhcount;
 		att->attidentity = entry->identity;
@@ -1381,24 +1380,6 @@ BuildDescForRelation(const List *columns)
 			att->attstorage = GetAttributeStorage(att->atttypid, entry->storage_name);
 	}
 
-	if (has_not_null)
-	{
-		TupleConstr *constr = (TupleConstr *) palloc0(sizeof(TupleConstr));
-
-		constr->has_not_null = true;
-		constr->has_generated_stored = false;
-		constr->defval = NULL;
-		constr->missing = NULL;
-		constr->num_defval = 0;
-		constr->check = NULL;
-		constr->num_check = 0;
-		desc->constr = constr;
-	}
-	else
-	{
-		desc->constr = NULL;
-	}
-
 	return desc;
 }
 
-- 
2.44.0


From 6960ee6add5801b9672db5dc94775f03b01ab91e Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <[email protected]>
Date: Mon, 29 Apr 2024 09:46:44 +0200
Subject: [PATCH v0 5/5] WIP: Virtual generated columns

This adds a new variant of generated columns that are computed on read
(like a view, unlike the existing stored generated columns, which are
computed on write, like a materialized view).
---
 contrib/pageinspect/expected/page.out         |  35 +
 contrib/pageinspect/sql/page.sql              |  17 +
 .../postgres_fdw/expected/postgres_fdw.out    |  81 +-
 contrib/postgres_fdw/sql/postgres_fdw.sql     |   9 +-
 doc/src/sgml/catalogs.sgml                    |   4 +-
 doc/src/sgml/ddl.sgml                         |   9 +-
 doc/src/sgml/ref/create_foreign_table.sgml    |  11 +-
 doc/src/sgml/ref/create_table.sgml            |  22 +-
 doc/src/sgml/ref/create_trigger.sgml          |   2 +-
 doc/src/sgml/trigger.sgml                     |   2 +
 src/backend/access/common/tupdesc.c           |   3 +
 src/backend/commands/indexcmds.c              |  29 +-
 src/backend/commands/tablecmds.c              |  39 +-
 src/backend/commands/trigger.c                |  48 +-
 src/backend/executor/execMain.c               |   5 +
 src/backend/parser/analyze.c                  |   8 +
 src/backend/parser/gram.y                     |  15 +-
 src/backend/parser/parse_clause.c             |   4 +
 src/backend/parser/parse_relation.c           |   9 +-
 src/backend/parser/parse_utilcmd.c            |  27 +-
 src/backend/rewrite/rewriteHandler.c          | 164 +++-
 src/backend/utils/cache/partcache.c           |   3 +
 src/backend/utils/cache/relcache.c            |   2 +
 src/bin/pg_dump/pg_dump.c                     |   3 +
 src/bin/pg_dump/t/002_pg_dump.pl              |   6 +-
 src/bin/psql/describe.c                       |   6 +
 src/include/access/tupdesc.h                  |   1 +
 src/include/catalog/pg_attribute.h            |   1 +
 src/include/nodes/parsenodes.h                |   3 +
 src/include/parser/kwlist.h                   |   1 +
 src/include/parser/parse_node.h               |   1 +
 src/include/rewrite/rewriteHandler.h          |   2 +
 src/pl/plperl/expected/plperl_trigger.out     |   7 +-
 src/pl/plperl/plperl.c                        |   3 +
 src/pl/plperl/sql/plperl_trigger.sql          |   3 +-
 src/pl/plpython/expected/plpython_trigger.out |   7 +-
 src/pl/plpython/plpy_typeio.c                 |   3 +
 src/pl/plpython/sql/plpython_trigger.sql      |   3 +-
 src/pl/tcl/expected/pltcl_trigger.out         |  19 +-
 src/pl/tcl/pltcl.c                            |   3 +
 src/pl/tcl/sql/pltcl_trigger.sql              |   3 +-
 .../regress/expected/create_table_like.out    |  23 +-
 .../regress/expected/generated_stored.out     |   2 +-
 ...rated_stored.out => generated_virtual.out} | 745 ++++++++----------
 src/test/regress/parallel_schedule            |   3 +
 src/test/regress/sql/create_table_like.sql    |   2 +-
 src/test/regress/sql/generated_stored.sql     |   2 +-
 ...rated_stored.sql => generated_virtual.sql} | 265 ++++---
 src/test/subscription/t/011_generated.pl      |  38 +-
 49 files changed, 1027 insertions(+), 676 deletions(-)
 copy src/test/regress/expected/{generated_stored.out => generated_virtual.out} (71%)
 copy src/test/regress/sql/{generated_stored.sql => generated_virtual.sql} (76%)

diff --git a/contrib/pageinspect/expected/page.out b/contrib/pageinspect/expected/page.out
index 80ddb45a60a..7e0b09e279b 100644
--- a/contrib/pageinspect/expected/page.out
+++ b/contrib/pageinspect/expected/page.out
@@ -208,6 +208,41 @@ select tuple_data_split('test8'::regclass, t_data, t_infomask, t_infomask2, t_bi
 (1 row)
 
 drop table test8;
+-- check storage of generated columns
+-- stored
+create table test9s (a int not null, b int generated always as (a * 2) stored);
+insert into test9s values (131584);
+select t_infomask, t_bits, t_data from heap_page_items(get_raw_page('test9s', 0));
+ t_infomask | t_bits |       t_data       
+------------+--------+--------------------
+       2048 |        | \x0002020000040400
+(1 row)
+
+select tuple_data_split('test9s'::regclass, t_data, t_infomask, t_infomask2, t_bits)
+    from heap_page_items(get_raw_page('test9s', 0));
+       tuple_data_split        
+-------------------------------
+ {"\\x00020200","\\x00040400"}
+(1 row)
+
+drop table test9s;
+-- virtual
+create table test9v (a int not null, b int generated always as (a * 2) virtual);
+insert into test9v values (131584);
+select t_infomask, t_bits, t_data from heap_page_items(get_raw_page('test9v', 0));
+ t_infomask |  t_bits  |   t_data   
+------------+----------+------------
+       2049 | 10000000 | \x00020200
+(1 row)
+
+select tuple_data_split('test9v'::regclass, t_data, t_infomask, t_infomask2, t_bits)
+    from heap_page_items(get_raw_page('test9v', 0));
+   tuple_data_split   
+----------------------
+ {"\\x00020200",NULL}
+(1 row)
+
+drop table test9v;
 -- Failure with incorrect page size
 -- Suppress the DETAIL message, to allow the tests to work across various
 -- page sizes.
diff --git a/contrib/pageinspect/sql/page.sql b/contrib/pageinspect/sql/page.sql
index 5bff568d3b5..186dda1e8d0 100644
--- a/contrib/pageinspect/sql/page.sql
+++ b/contrib/pageinspect/sql/page.sql
@@ -84,6 +84,23 @@ CREATE TEMP TABLE test1 (a int, b int);
     from heap_page_items(get_raw_page('test8', 0));
 drop table test8;
 
+-- check storage of generated columns
+-- stored
+create table test9s (a int not null, b int generated always as (a * 2) stored);
+insert into test9s values (131584);
+select t_infomask, t_bits, t_data from heap_page_items(get_raw_page('test9s', 0));
+select tuple_data_split('test9s'::regclass, t_data, t_infomask, t_infomask2, t_bits)
+    from heap_page_items(get_raw_page('test9s', 0));
+drop table test9s;
+
+-- virtual
+create table test9v (a int not null, b int generated always as (a * 2) virtual);
+insert into test9v values (131584);
+select t_infomask, t_bits, t_data from heap_page_items(get_raw_page('test9v', 0));
+select tuple_data_split('test9v'::regclass, t_data, t_infomask, t_infomask2, t_bits)
+    from heap_page_items(get_raw_page('test9v', 0));
+drop table test9v;
+
 -- Failure with incorrect page size
 -- Suppress the DETAIL message, to allow the tests to work across various
 -- page sizes.
diff --git a/contrib/postgres_fdw/expected/postgres_fdw.out b/contrib/postgres_fdw/expected/postgres_fdw.out
index 078b8a966f8..7a3e71c07b4 100644
--- a/contrib/postgres_fdw/expected/postgres_fdw.out
+++ b/contrib/postgres_fdw/expected/postgres_fdw.out
@@ -7215,65 +7215,68 @@ select * from rem1;
 -- ===================================================================
 create table gloc1 (
   a int,
-  b int generated always as (a * 2) stored);
+  b int generated always as (a * 2) stored,
+  c int
+);
 alter table gloc1 set (autovacuum_enabled = 'false');
 create foreign table grem1 (
   a int,
-  b int generated always as (a * 2) stored)
-  server loopback options(table_name 'gloc1');
+  b int generated always as (a * 2) stored,
+  c int generated always as (a * 3) virtual
+) server loopback options(table_name 'gloc1');
 explain (verbose, costs off)
 insert into grem1 (a) values (1), (2);
-                            QUERY PLAN                             
--------------------------------------------------------------------
+                                  QUERY PLAN                                   
+-------------------------------------------------------------------------------
  Insert on public.grem1
-   Remote SQL: INSERT INTO public.gloc1(a, b) VALUES ($1, DEFAULT)
+   Remote SQL: INSERT INTO public.gloc1(a, b, c) VALUES ($1, DEFAULT, DEFAULT)
    Batch Size: 1
    ->  Values Scan on "*VALUES*"
-         Output: "*VALUES*".column1, NULL::integer
+         Output: "*VALUES*".column1, NULL::integer, NULL::integer
 (5 rows)
 
 insert into grem1 (a) values (1), (2);
 explain (verbose, costs off)
 update grem1 set a = 22 where a = 2;
-                                     QUERY PLAN                                     
-------------------------------------------------------------------------------------
+                                       QUERY PLAN                                       
+----------------------------------------------------------------------------------------
  Update on public.grem1
-   Remote SQL: UPDATE public.gloc1 SET a = $2, b = DEFAULT WHERE ctid = $1
+   Remote SQL: UPDATE public.gloc1 SET a = $2, b = DEFAULT, c = DEFAULT WHERE ctid = $1
    ->  Foreign Scan on public.grem1
          Output: 22, ctid, grem1.*
-         Remote SQL: SELECT a, b, ctid FROM public.gloc1 WHERE ((a = 2)) FOR UPDATE
+         Remote SQL: SELECT a, b, c, ctid FROM public.gloc1 WHERE ((a = 2)) FOR UPDATE
 (5 rows)
 
 update grem1 set a = 22 where a = 2;
 select * from gloc1;
- a  | b  
-----+----
-  1 |  2
- 22 | 44
+ a  | b  | c 
+----+----+---
+  1 |  2 |  
+ 22 | 44 |  
 (2 rows)
 
 select * from grem1;
- a  | b  
-----+----
-  1 |  2
- 22 | 44
+ a  | b  | c  
+----+----+----
+  1 |  2 |  3
+ 22 | 44 | 66
 (2 rows)
 
 delete from grem1;
 -- test copy from
 copy grem1 from stdin;
 select * from gloc1;
- a | b 
----+---
- 1 | 2
- 2 | 4
+ a | b | c 
+---+---+---
+ 1 | 2 |  
+ 2 | 4 |  
 (2 rows)
 
 select * from grem1;
- a | b 
----+---
- 1 | 2
- 2 | 4
+ a | b | c 
+---+---+---
+ 1 | 2 | 3
+ 2 | 4 | 6
 (2 rows)
 
 delete from grem1;
@@ -7281,28 +7284,28 @@ delete from grem1;
 alter server loopback options (add batch_size '10');
 explain (verbose, costs off)
 insert into grem1 (a) values (1), (2);
-                            QUERY PLAN                             
--------------------------------------------------------------------
+                                  QUERY PLAN                                   
+-------------------------------------------------------------------------------
  Insert on public.grem1
-   Remote SQL: INSERT INTO public.gloc1(a, b) VALUES ($1, DEFAULT)
+   Remote SQL: INSERT INTO public.gloc1(a, b, c) VALUES ($1, DEFAULT, DEFAULT)
    Batch Size: 10
    ->  Values Scan on "*VALUES*"
-         Output: "*VALUES*".column1, NULL::integer
+         Output: "*VALUES*".column1, NULL::integer, NULL::integer
 (5 rows)
 
 insert into grem1 (a) values (1), (2);
 select * from gloc1;
- a | b 
----+---
- 1 | 2
- 2 | 4
+ a | b | c 
+---+---+---
+ 1 | 2 |  
+ 2 | 4 |  
 (2 rows)
 
 select * from grem1;
- a | b 
----+---
- 1 | 2
- 2 | 4
+ a | b | c 
+---+---+---
+ 1 | 2 | 3
+ 2 | 4 | 6
 (2 rows)
 
 delete from grem1;
diff --git a/contrib/postgres_fdw/sql/postgres_fdw.sql b/contrib/postgres_fdw/sql/postgres_fdw.sql
index 09ba234e43d..1fc28b3e264 100644
--- a/contrib/postgres_fdw/sql/postgres_fdw.sql
+++ b/contrib/postgres_fdw/sql/postgres_fdw.sql
@@ -1806,12 +1806,15 @@ CREATE VIEW rw_view AS SELECT * FROM parent_tbl WHERE a < 5 WITH CHECK OPTION;
 -- ===================================================================
 create table gloc1 (
   a int,
-  b int generated always as (a * 2) stored);
+  b int generated always as (a * 2) stored,
+  c int
+);
 alter table gloc1 set (autovacuum_enabled = 'false');
 create foreign table grem1 (
   a int,
-  b int generated always as (a * 2) stored)
-  server loopback options(table_name 'gloc1');
+  b int generated always as (a * 2) stored,
+  c int generated always as (a * 3) virtual
+) server loopback options(table_name 'gloc1');
 explain (verbose, costs off)
 insert into grem1 (a) values (1), (2);
 insert into grem1 (a) values (1), (2);
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 2907079e2a6..2b93c05be42 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -1318,8 +1318,8 @@ <title><structname>pg_attribute</structname> Columns</title>
       </para>
       <para>
        If a zero byte (<literal>''</literal>), then not a generated column.
-       Otherwise, <literal>s</literal> = stored.  (Other values might be added
-       in the future.)
+       Otherwise, <literal>s</literal> = stored, <literal>v</literal> =
+       virtual.
       </para></entry>
      </row>
 
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 026bfff70f3..4449d70f235 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -361,7 +361,6 @@ <title>Generated Columns</title>
    storage and is computed when it is read.  Thus, a virtual generated column
    is similar to a view and a stored generated column is similar to a
    materialized view (except that it is always updated automatically).
-   <productname>PostgreSQL</productname> currently implements only stored generated columns.
   </para>
 
   <para>
@@ -371,12 +370,12 @@ <title>Generated Columns</title>
 CREATE TABLE people (
     ...,
     height_cm numeric,
-    height_in numeric <emphasis>GENERATED ALWAYS AS (height_cm / 2.54) STORED</emphasis>
+    height_in numeric <emphasis>GENERATED ALWAYS AS (height_cm / 2.54)</emphasis>
 );
 </programlisting>
-   The keyword <literal>STORED</literal> must be specified to choose the
-   stored kind of generated column.  See <xref linkend="sql-createtable"/> for
-   more details.
+   A generated column is by default of the virtual kind.  Use the keywords
+   <literal>VIRTUAL</literal> or <literal>STORED</literal> to make the choice
+   explicit.  See <xref linkend="sql-createtable"/> for more details.
   </para>
 
   <para>
diff --git a/doc/src/sgml/ref/create_foreign_table.sgml b/doc/src/sgml/ref/create_foreign_table.sgml
index dc4b9075990..21b5d6a14d0 100644
--- a/doc/src/sgml/ref/create_foreign_table.sgml
+++ b/doc/src/sgml/ref/create_foreign_table.sgml
@@ -47,7 +47,7 @@
   NULL |
   CHECK ( <replaceable class="parameter">expression</replaceable> ) [ NO INHERIT ] |
   DEFAULT <replaceable>default_expr</replaceable> |
-  GENERATED ALWAYS AS ( <replaceable>generation_expr</replaceable> ) STORED }
+  GENERATED ALWAYS AS ( <replaceable>generation_expr</replaceable> ) [ STORED | VIRTUAL ] }
 
 <phrase>and <replaceable class="parameter">table_constraint</replaceable> is:</phrase>
 
@@ -275,7 +275,7 @@ <title>Parameters</title>
    </varlistentry>
 
    <varlistentry>
-    <term><literal>GENERATED ALWAYS AS ( <replaceable>generation_expr</replaceable> ) STORED</literal><indexterm><primary>generated column</primary></indexterm></term>
+    <term><literal>GENERATED ALWAYS AS ( <replaceable>generation_expr</replaceable> ) [ STORED | VIRTUAL ]</literal><indexterm><primary>generated column</primary></indexterm></term>
     <listitem>
      <para>
       This clause creates the column as a <firstterm>generated
@@ -284,10 +284,13 @@ <title>Parameters</title>
      </para>
 
      <para>
-      The keyword <literal>STORED</literal> is required to signify that the
+      When <literal>VIRTUAL</literal> is specified, the column will be
+      computed when it is read.  (The foreign-data wrapper will see it as a
+      null value in new rows and may choose to store it as a null value or
+      ignore it altogether.)  When <literal>STORED</literal> is specified, the
       column will be computed on write.  (The computed value will be presented
       to the foreign-data wrapper for storage and must be returned on
-      reading.)
+      reading.)  <literal>VIRTUAL</literal> is the default.
      </para>
 
      <para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 02f31d2d6fd..a69b41f4973 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -65,7 +65,7 @@
   NULL |
   CHECK ( <replaceable class="parameter">expression</replaceable> ) [ NO INHERIT ] |
   DEFAULT <replaceable>default_expr</replaceable> |
-  GENERATED ALWAYS AS ( <replaceable>generation_expr</replaceable> ) STORED |
+  GENERATED ALWAYS AS ( <replaceable>generation_expr</replaceable> ) [ STORED | VIRTUAL ] |
   GENERATED { ALWAYS | BY DEFAULT } AS IDENTITY [ ( <replaceable>sequence_options</replaceable> ) ] |
   UNIQUE [ NULLS [ NOT ] DISTINCT ] <replaceable class="parameter">index_parameters</replaceable> |
   PRIMARY KEY <replaceable class="parameter">index_parameters</replaceable> |
@@ -721,8 +721,9 @@ <title>Parameters</title>
         <term><literal>INCLUDING GENERATED</literal></term>
         <listitem>
          <para>
-          Any generation expressions of copied column definitions will be
-          copied.  By default, new columns will be regular base columns.
+          Any generation expressions as well as the stored/virtual choice of
+          copied column definitions will be copied.  By default, new columns
+          will be regular base columns.
          </para>
         </listitem>
        </varlistentry>
@@ -898,7 +899,7 @@ <title>Parameters</title>
    </varlistentry>
 
    <varlistentry id="sql-createtable-parms-generated-stored">
-    <term><literal>GENERATED ALWAYS AS ( <replaceable>generation_expr</replaceable> ) STORED</literal><indexterm><primary>generated column</primary></indexterm></term>
+    <term><literal>GENERATED ALWAYS AS ( <replaceable>generation_expr</replaceable> ) [ STORED | VIRTUAL ]</literal><indexterm><primary>generated column</primary></indexterm></term>
     <listitem>
      <para>
       This clause creates the column as a <firstterm>generated
@@ -907,8 +908,11 @@ <title>Parameters</title>
      </para>
 
      <para>
-      The keyword <literal>STORED</literal> is required to signify that the
-      column will be computed on write and will be stored on disk.
+      When <literal>VIRTUAL</literal> is specified, the column will be
+      computed when it is read, and it will not occupy any storage.  When
+      <literal>STORED</literal> is specified, the column will be computed on
+      write and will be stored on disk.  <literal>VIRTUAL</literal> is the
+      default.
      </para>
 
      <para>
@@ -2436,9 +2440,9 @@ <title>Multiple Identity Columns</title>
    <title>Generated Columns</title>
 
    <para>
-    The option <literal>STORED</literal> is not standard but is also used by
-    other SQL implementations.  The SQL standard does not specify the storage
-    of generated columns.
+    The options <literal>STORED</literal> and <literal>VIRTUAL</literal> are
+    not standard but are also used by other SQL implementations.  The SQL
+    standard does not specify the storage of generated columns.
    </para>
   </refsect2>
 
diff --git a/doc/src/sgml/ref/create_trigger.sgml b/doc/src/sgml/ref/create_trigger.sgml
index 982ab6f3ee4..752fe50860a 100644
--- a/doc/src/sgml/ref/create_trigger.sgml
+++ b/doc/src/sgml/ref/create_trigger.sgml
@@ -279,7 +279,7 @@ <title>Parameters</title>
      <para>
       <literal>INSTEAD OF UPDATE</literal> events do not allow a list of columns.
       A column list cannot be specified when requesting transition relations,
-      either.
+      either.  Virtual generated columns are not supported in the column list.
      </para>
     </listitem>
    </varlistentry>
diff --git a/doc/src/sgml/trigger.sgml b/doc/src/sgml/trigger.sgml
index a5390ff6443..a758fda914f 100644
--- a/doc/src/sgml/trigger.sgml
+++ b/doc/src/sgml/trigger.sgml
@@ -289,6 +289,8 @@ <title>Overview of Trigger Behavior</title>
     <literal>BEFORE</literal> trigger.  Changes to the value of a generated
     column in a <literal>BEFORE</literal> trigger are ignored and will be
     overwritten.
+    Virtual generated columns are never computed when triggers fire; they will
+    always appear as null inside a trigger function.
    </para>
 
    <para>
diff --git a/src/backend/access/common/tupdesc.c b/src/backend/access/common/tupdesc.c
index 47379fef220..13840ba533c 100644
--- a/src/backend/access/common/tupdesc.c
+++ b/src/backend/access/common/tupdesc.c
@@ -190,6 +190,7 @@ CreateTupleDescCopyConstr(TupleDesc tupdesc)
 
 		cpy->has_not_null = constr->has_not_null;
 		cpy->has_generated_stored = constr->has_generated_stored;
+		cpy->has_generated_virtual = constr->has_generated_virtual;
 
 		if ((cpy->num_defval = constr->num_defval) > 0)
 		{
@@ -494,6 +495,8 @@ equalTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2)
 			return false;
 		if (constr1->has_generated_stored != constr2->has_generated_stored)
 			return false;
+		if (constr1->has_generated_virtual != constr2->has_generated_virtual)
+			return false;
 		n = constr1->num_defval;
 		if (n != (int) constr2->num_defval)
 			return false;
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index d9016ef487b..dd9d042cad4 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -1097,6 +1097,9 @@ DefineIndex(Oid tableId,
 	/*
 	 * We disallow indexes on system columns.  They would not necessarily get
 	 * updated correctly, and they don't seem useful anyway.
+	 *
+	 * Also disallow virtual generated columns in indexes (use expression
+	 * index instead).
 	 */
 	for (int i = 0; i < indexInfo->ii_NumIndexAttrs; i++)
 	{
@@ -1106,14 +1109,22 @@ DefineIndex(Oid tableId,
 			ereport(ERROR,
 					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 					 errmsg("index creation on system columns is not supported")));
+
+
+		if (TupleDescAttr(RelationGetDescr(rel), attno - 1)->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("index creation on virtual generated columns is not supported")));
 	}
 
 	/*
-	 * Also check for system columns used in expressions or predicates.
+	 * Also check for system and generated columns used in expressions or
+	 * predicates.
 	 */
 	if (indexInfo->ii_Expressions || indexInfo->ii_Predicate)
 	{
 		Bitmapset  *indexattrs = NULL;
+		int			j;
 
 		pull_varattnos((Node *) indexInfo->ii_Expressions, 1, &indexattrs);
 		pull_varattnos((Node *) indexInfo->ii_Predicate, 1, &indexattrs);
@@ -1126,6 +1137,22 @@ DefineIndex(Oid tableId,
 						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 						 errmsg("index creation on system columns is not supported")));
 		}
+
+		/*
+		 * XXX Virtual generated columns in index expressions or predicates
+		 * could be supported, but it needs support in
+		 * RelationGetIndexExpressions() and RelationGetIndexPredicate().
+		 */
+		j = -1;
+		while ((j = bms_next_member(indexattrs, j)) >= 0)
+		{
+			AttrNumber	attno = j + FirstLowInvalidHeapAttributeNumber;
+
+			if (TupleDescAttr(RelationGetDescr(rel), attno - 1)->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("index creation on virtual generated columns is not supported")));
+		}
 	}
 
 	/* Is index safe for others to ignore?  See set_indexsafe_procflags() */
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 4ec600e21d1..b597a4ee80a 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -6093,7 +6093,7 @@ ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap, LOCKMODE lockmode)
 		{
 			case CONSTR_CHECK:
 				needscan = true;
-				con->qualstate = ExecPrepareExpr((Expr *) con->qual, estate);
+				con->qualstate = ExecPrepareExpr((Expr *) expand_generated_columns_in_expr(con->qual, newrel ? newrel : oldrel), estate);
 				break;
 			case CONSTR_FOREIGN:
 				/* Nothing to do here */
@@ -7590,6 +7590,8 @@ ATExecDropNotNull(Relation rel, const char *colName, bool recurse,
 				 errmsg("cannot alter system column \"%s\"",
 						colName)));
 
+	// FIXME: virtual generated columns
+
 	if (attTup->attidentity)
 		ereport(ERROR,
 				(errcode(ERRCODE_SYNTAX_ERROR),
@@ -7849,6 +7851,8 @@ ATExecSetNotNull(List **wqueue, Relation rel, char *conName, char *colName,
 				 errmsg("cannot alter system column \"%s\"",
 						colName)));
 
+	// FIXME: virtual generated columns
+
 	/* See if there's already a constraint */
 	constr_rel = table_open(ConstraintRelationId, RowExclusiveLock);
 	ScanKeyInit(&skey,
@@ -8545,6 +8549,7 @@ ATExecSetExpression(AlteredTableInfo *tab, Relation rel, const char *colName,
 				 errmsg("cannot alter system column \"%s\"",
 						colName)));
 
+	// FIXME
 	if (attTup->attgenerated != ATTRIBUTE_GENERATED_STORED)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
@@ -10064,6 +10069,19 @@ ATAddForeignKeyConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
 						 errmsg("invalid %s action for foreign key constraint containing generated column",
 								"ON DELETE")));
 		}
+
+		/*
+		 * FKs on virtual columns are not supported.  This would require
+		 * various additional support in ri_triggers.c, including special
+		 * handling in ri_NullCheck(), ri_KeysEqual(),
+		 * RI_FKey_fk_upd_check_required() (since all virtual columns appear
+		 * as NULL there).  Also not really practical as long as you can't
+		 * index virtual columns.
+		 */
+		if (attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("foreign key constraints on virtual generated columns are not supported")));
 	}
 
 	/*
@@ -12119,7 +12137,7 @@ ATExecValidateConstraint(List **wqueue, Relation rel, char *constrName,
 			val = SysCacheGetAttrNotNull(CONSTROID, tuple,
 										 Anum_pg_constraint_conbin);
 			conbin = TextDatumGetCString(val);
-			newcon->qual = (Node *) stringToNode(conbin);
+			newcon->qual = (Node *) expand_generated_columns_in_expr(stringToNode(conbin), rel);
 
 			/* Find or create work queue entry for this table */
 			tab = ATGetQueueEntry(wqueue, rel);
@@ -13438,6 +13456,7 @@ ATPrepAlterColumnType(List **wqueue,
 					   list_make1_oid(rel->rd_rel->reltype),
 					   0);
 
+	// FIXME
 	if (tab->relkind == RELKIND_RELATION ||
 		tab->relkind == RELKIND_PARTITIONED_TABLE)
 	{
@@ -18748,8 +18767,11 @@ ComputePartitionAttrs(ParseState *pstate, Relation rel, List *partParams, AttrNu
 						 parser_errposition(pstate, pelem->location)));
 
 			/*
-			 * Generated columns cannot work: They are computed after BEFORE
-			 * triggers, but partition routing is done before all triggers.
+			 * Stored generated columns cannot work: They are computed after
+			 * BEFORE triggers, but partition routing is done before all
+			 * triggers.  Maybe virtual generated columns could be made to
+			 * work, but then they would need to be handled as an expression
+			 * below.
 			 */
 			if (attform->attgenerated)
 				ereport(ERROR,
@@ -18831,9 +18853,12 @@ ComputePartitionAttrs(ParseState *pstate, Relation rel, List *partParams, AttrNu
 				}
 
 				/*
-				 * Generated columns cannot work: They are computed after
-				 * BEFORE triggers, but partition routing is done before all
-				 * triggers.
+				 * Stored generated columns cannot work: They are computed
+				 * after BEFORE triggers, but partition routing is done before
+				 * all triggers.  Virtual generated columns could probably
+				 * work, but it would require more work elsewhere (for example
+				 * SET EXPRESSION would need to check whether the column is
+				 * used in partition keys).  Seems safer to prohibit for now.
 				 */
 				i = -1;
 				while ((i = bms_next_member(expr_attrs, i)) >= 0)
diff --git a/src/backend/commands/trigger.c b/src/backend/commands/trigger.c
index 35eb7180f7e..e26dbadea40 100644
--- a/src/backend/commands/trigger.c
+++ b/src/backend/commands/trigger.c
@@ -43,6 +43,7 @@
 #include "parser/parse_relation.h"
 #include "partitioning/partdesc.h"
 #include "pgstat.h"
+#include "rewrite/rewriteHandler.h"
 #include "rewrite/rewriteManip.h"
 #include "storage/lmgr.h"
 #include "utils/acl.h"
@@ -101,6 +102,7 @@ static void AfterTriggerSaveEvent(EState *estate, ResultRelInfo *relinfo,
 								  bool is_crosspart_update);
 static void AfterTriggerEnlargeQueryState(void);
 static bool before_stmt_triggers_fired(Oid relid, CmdType cmdType);
+static void check_modified_virtual_generated(TupleDesc tupdesc, HeapTuple tuple);
 
 
 /*
@@ -641,7 +643,8 @@ CreateTriggerFiringOn(CreateTrigStmt *stmt, const char *queryString,
 					if (TRIGGER_FOR_BEFORE(tgtype) &&
 						var->varattno == 0 &&
 						RelationGetDescr(rel)->constr &&
-						RelationGetDescr(rel)->constr->has_generated_stored)
+						(RelationGetDescr(rel)->constr->has_generated_stored ||
+						 RelationGetDescr(rel)->constr->has_generated_virtual))
 						ereport(ERROR,
 								(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
 								 errmsg("BEFORE trigger's WHEN condition cannot reference NEW generated columns"),
@@ -943,6 +946,13 @@ CreateTriggerFiringOn(CreateTrigStmt *stmt, const char *queryString,
 						 errmsg("column \"%s\" of relation \"%s\" does not exist",
 								name, RelationGetRelationName(rel))));
 
+			/* Currently doesn't work. */
+			if (TupleDescAttr(RelationGetDescr(rel), attnum - 1)->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
+				ereport(ERROR,
+						errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						errmsg("virtual generated columns are not supported as trigger columns"),
+						errdetail("Column \"%s\" is a virtual generated column.", name));
+
 			/* Check for duplicates */
 			for (j = i - 1; j >= 0; j--)
 			{
@@ -2502,6 +2512,8 @@ ExecBRInsertTriggers(EState *estate, ResultRelInfo *relinfo,
 		}
 		else if (newtuple != oldtuple)
 		{
+			check_modified_virtual_generated(RelationGetDescr(relinfo->ri_RelationDesc), newtuple);
+
 			ExecForceStoreHeapTuple(newtuple, slot, false);
 
 			/*
@@ -3059,6 +3071,8 @@ ExecBRUpdateTriggers(EState *estate, EPQState *epqstate,
 		}
 		else if (newtuple != oldtuple)
 		{
+			check_modified_virtual_generated(RelationGetDescr(relinfo->ri_RelationDesc), newtuple);
+
 			ExecForceStoreHeapTuple(newtuple, newslot, false);
 
 			/*
@@ -3489,6 +3503,7 @@ TriggerEnabled(EState *estate, ResultRelInfo *relinfo,
 
 			oldContext = MemoryContextSwitchTo(estate->es_query_cxt);
 			tgqual = stringToNode(trigger->tgqual);
+			tgqual = (Node *) expand_generated_columns_in_expr(tgqual, relinfo->ri_RelationDesc);
 			/* Change references to OLD and NEW to INNER_VAR and OUTER_VAR */
 			ChangeVarNodes(tgqual, PRS2_OLD_VARNO, INNER_VAR, 0);
 			ChangeVarNodes(tgqual, PRS2_NEW_VARNO, OUTER_VAR, 0);
@@ -6594,3 +6609,34 @@ pg_trigger_depth(PG_FUNCTION_ARGS)
 {
 	PG_RETURN_INT32(MyTriggerDepth);
 }
+
+/*
+ * Check whether a trigger modified a virtual generated column and error if
+ * so.
+ *
+ * We need to check this so that we don't end up storing a non-null value in a
+ * virtual generated column.
+ *
+ * We don't need to check for stored generated columns, since those will be
+ * overwritten later anyway.
+ */
+static void
+check_modified_virtual_generated(TupleDesc tupdesc, HeapTuple tuple)
+{
+	if (!(tupdesc->constr && tupdesc->constr->has_generated_virtual))
+		return;
+
+	for (int i = 0; i < tupdesc->natts; i++)
+	{
+		if (TupleDescAttr(tupdesc, i)->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
+		{
+			bool		isnull;
+
+			fastgetattr(tuple, i + 1, tupdesc, &isnull);
+			if (!isnull)
+				ereport(ERROR,
+						(errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
+						 errmsg("trigger modified virtual generated column value")));
+		}
+	}
+}
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index 4d7c92d63c1..fbcce675540 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -1748,6 +1748,7 @@ ExecRelCheck(ResultRelInfo *resultRelInfo,
 			Expr	   *checkconstr;
 
 			checkconstr = stringToNode(check[i].ccbin);
+			checkconstr = (Expr *) expand_generated_columns_in_expr((Node *) checkconstr, rel);
 			resultRelInfo->ri_ConstraintExprs[i] =
 				ExecPrepareExpr(checkconstr, estate);
 		}
@@ -2269,6 +2270,10 @@ ExecBuildSlotValueDescription(Oid reloid,
 		if (att->attisdropped)
 			continue;
 
+		/* ignore virtual generated columns; they are always null here */
+		if (att->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
+			continue;
+
 		if (!table_perm)
 		{
 			/*
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index 28fed9d87f6..01dedbfc396 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -562,6 +562,7 @@ transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt)
 	qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
 	qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
 	qry->hasAggs = pstate->p_hasAggs;
+	qry->hasGeneratedVirtual = pstate->p_hasGeneratedVirtual;
 
 	assign_query_collations(pstate, qry);
 
@@ -988,6 +989,7 @@ transformInsertStmt(ParseState *pstate, InsertStmt *stmt)
 
 	qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
 	qry->hasSubLinks = pstate->p_hasSubLinks;
+	qry->hasGeneratedVirtual = pstate->p_hasGeneratedVirtual;
 
 	assign_query_collations(pstate, qry);
 
@@ -1453,6 +1455,7 @@ transformSelectStmt(ParseState *pstate, SelectStmt *stmt)
 	qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
 	qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
 	qry->hasAggs = pstate->p_hasAggs;
+	qry->hasGeneratedVirtual = pstate->p_hasGeneratedVirtual;
 
 	foreach(l, stmt->lockingClause)
 	{
@@ -1679,6 +1682,7 @@ transformValuesClause(ParseState *pstate, SelectStmt *stmt)
 	qry->jointree = makeFromExpr(pstate->p_joinlist, NULL);
 
 	qry->hasSubLinks = pstate->p_hasSubLinks;
+	qry->hasGeneratedVirtual = pstate->p_hasGeneratedVirtual;
 
 	assign_query_collations(pstate, qry);
 
@@ -1930,6 +1934,7 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt)
 	qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
 	qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
 	qry->hasAggs = pstate->p_hasAggs;
+	qry->hasGeneratedVirtual = pstate->p_hasGeneratedVirtual;
 
 	foreach(l, lockingClause)
 	{
@@ -2404,6 +2409,7 @@ transformReturnStmt(ParseState *pstate, ReturnStmt *stmt)
 	qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
 	qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
 	qry->hasAggs = pstate->p_hasAggs;
+	qry->hasGeneratedVirtual = pstate->p_hasGeneratedVirtual;
 
 	assign_query_collations(pstate, qry);
 
@@ -2471,6 +2477,7 @@ transformUpdateStmt(ParseState *pstate, UpdateStmt *stmt)
 
 	qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
 	qry->hasSubLinks = pstate->p_hasSubLinks;
+	qry->hasGeneratedVirtual = pstate->p_hasGeneratedVirtual;
 
 	assign_query_collations(pstate, qry);
 
@@ -2837,6 +2844,7 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt)
 	qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
 	qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
 	qry->hasAggs = pstate->p_hasAggs;
+	qry->hasGeneratedVirtual = pstate->p_hasGeneratedVirtual;
 
 	foreach(l, sstmt->lockingClause)
 	{
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index e8b619926ef..9643b2ae65d 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -642,7 +642,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 %type <str>		opt_existing_window_name
 %type <boolean> opt_if_not_exists
 %type <boolean> opt_unique_null_treatment
-%type <ival>	generated_when override_kind
+%type <ival>	generated_when override_kind opt_virtual_or_stored
 %type <partspec>	PartitionSpec OptPartitionSpec
 %type <partelem>	part_elem
 %type <list>		part_params
@@ -793,7 +793,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	UNLISTEN UNLOGGED UNTIL UPDATE USER USING
 
 	VACUUM VALID VALIDATE VALIDATOR VALUE_P VALUES VARCHAR VARIADIC VARYING
-	VERBOSE VERSION_P VIEW VIEWS VOLATILE
+	VERBOSE VERSION_P VIEW VIEWS VIRTUAL VOLATILE
 
 	WHEN WHERE WHITESPACE_P WINDOW WITH WITHIN WITHOUT WORK WRAPPER WRITE
 
@@ -4030,7 +4030,7 @@ ColConstraintElem:
 					n->location = @1;
 					$$ = (Node *) n;
 				}
-			| GENERATED generated_when AS '(' a_expr ')' STORED
+			| GENERATED generated_when AS '(' a_expr ')' opt_virtual_or_stored
 				{
 					Constraint *n = makeNode(Constraint);
 
@@ -4038,6 +4038,7 @@ ColConstraintElem:
 					n->generated_when = $2;
 					n->raw_expr = $5;
 					n->cooked_expr = NULL;
+					n->generated_kind = $7;
 					n->location = @1;
 
 					/*
@@ -4084,6 +4085,12 @@ generated_when:
 			| BY DEFAULT	{ $$ = ATTRIBUTE_IDENTITY_BY_DEFAULT; }
 		;
 
+opt_virtual_or_stored:
+			STORED			{ $$ = ATTRIBUTE_GENERATED_STORED; }
+			| VIRTUAL		{ $$ = ATTRIBUTE_GENERATED_VIRTUAL; }
+			| /*EMPTY*/		{ $$ = ATTRIBUTE_GENERATED_VIRTUAL; }
+		;
+
 /*
  * ConstraintAttr represents constraint attributes, which we parse as if
  * they were independent constraint clauses, in order to avoid shift/reduce
@@ -17929,6 +17936,7 @@ unreserved_keyword:
 			| VERSION_P
 			| VIEW
 			| VIEWS
+			| VIRTUAL
 			| VOLATILE
 			| WHITESPACE_P
 			| WITHIN
@@ -18586,6 +18594,7 @@ bare_label_keyword:
 			| VERSION_P
 			| VIEW
 			| VIEWS
+			| VIRTUAL
 			| VOLATILE
 			| WHEN
 			| WHITESPACE_P
diff --git a/src/backend/parser/parse_clause.c b/src/backend/parser/parse_clause.c
index 4fc5fc87e07..0a54eb0c533 100644
--- a/src/backend/parser/parse_clause.c
+++ b/src/backend/parser/parse_clause.c
@@ -207,6 +207,10 @@ setTargetTable(ParseState *pstate, RangeVar *relation,
 	pstate->p_target_relation = parserOpenTable(pstate, relation,
 												RowExclusiveLock);
 
+	if (pstate->p_target_relation->rd_att->constr &&
+		pstate->p_target_relation->rd_att->constr->has_generated_virtual)
+		pstate->p_hasGeneratedVirtual = true;
+
 	/*
 	 * Now build an RTE and a ParseNamespaceItem.
 	 */
diff --git a/src/backend/parser/parse_relation.c b/src/backend/parser/parse_relation.c
index 2f64eaf0e37..b864749f09c 100644
--- a/src/backend/parser/parse_relation.c
+++ b/src/backend/parser/parse_relation.c
@@ -704,7 +704,11 @@ scanNSItemForColumn(ParseState *pstate, ParseNamespaceItem *nsitem,
 						colname),
 				 parser_errposition(pstate, location)));
 
-	/* In generated column, no system column is allowed except tableOid */
+	/*
+	 * In generated column, no system column is allowed except tableOid.
+	 * (Required for stored generated, but we also do it for virtual generated
+	 * for now for consistency.)
+	 */
 	if (pstate->p_expr_kind == EXPR_KIND_GENERATED_COLUMN &&
 		attnum < InvalidAttrNumber && attnum != TableOidAttributeNumber)
 		ereport(ERROR,
@@ -1511,6 +1515,9 @@ addRangeTableEntry(ParseState *pstate,
 	rte->eref = makeAlias(refname, NIL);
 	buildRelationAliases(rel->rd_att, alias, rte->eref);
 
+	if (rel->rd_att->constr && rel->rd_att->constr->has_generated_virtual)
+		pstate->p_hasGeneratedVirtual = true;
+
 	/*
 	 * Set flags and initialize access permissions.
 	 *
diff --git a/src/backend/parser/parse_utilcmd.c b/src/backend/parser/parse_utilcmd.c
index fef084f5d52..ec24fda3015 100644
--- a/src/backend/parser/parse_utilcmd.c
+++ b/src/backend/parser/parse_utilcmd.c
@@ -786,10 +786,33 @@ transformColumnDefinition(CreateStmtContext *cxt, ColumnDef *column)
 									column->colname, cxt->relation->relname),
 							 parser_errposition(cxt->pstate,
 												constraint->location)));
-				column->generated = ATTRIBUTE_GENERATED_STORED;
+				column->generated = constraint->generated_kind;
 				column->raw_default = constraint->raw_expr;
 				Assert(constraint->cooked_expr == NULL);
 				saw_generated = true;
+
+#if FIXME
+				/*
+				 * Prevent virtual generated columns from having a domain
+				 * type.  We would have to enforce domain constraints when
+				 * columns underlying the generated column change.  This could
+				 * possibly be implemented, but it's not.
+				 */
+				if (column->generated == ATTRIBUTE_GENERATED_VIRTUAL)
+				{
+					Type		ctype;
+
+					ctype = typenameType(cxt->pstate, column->typeName, NULL);
+					if (((Form_pg_type) GETSTRUCT(ctype))->typtype == TYPTYPE_DOMAIN)
+						ereport(ERROR,
+								(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+								 errmsg("virtual generated column \"%s\" cannot have a domain type",
+										column->colname),
+								 parser_errposition(cxt->pstate,
+													column->location)));
+					ReleaseSysCache(ctype);
+				}
+#endif
 				break;
 
 			case CONSTR_CHECK:
@@ -874,6 +897,8 @@ transformColumnDefinition(CreateStmtContext *cxt, ColumnDef *column)
 							column->colname, cxt->relation->relname),
 					 parser_errposition(cxt->pstate,
 										constraint->location)));
+
+		// TODO: not-null constraints on virtual generated columns (see v8 patch)
 	}
 
 	/*
diff --git a/src/backend/rewrite/rewriteHandler.c b/src/backend/rewrite/rewriteHandler.c
index 9fd05b15e73..7dc381ecf60 100644
--- a/src/backend/rewrite/rewriteHandler.c
+++ b/src/backend/rewrite/rewriteHandler.c
@@ -90,6 +90,8 @@ static List *matchLocks(CmdType event, Relation relation,
 						int varno, Query *parsetree, bool *hasUpdate);
 static Query *fireRIRrules(Query *parsetree, List *activeRIRs);
 static Bitmapset *adjust_view_column_set(Bitmapset *cols, List *targetlist);
+struct expand_generated_context;
+static Query *expand_generated_columns_in_query(Query *query, struct expand_generated_context *context);
 
 
 /*
@@ -974,7 +976,8 @@ rewriteTargetListIU(List *targetList,
 		if (att_tup->attgenerated)
 		{
 			/*
-			 * stored generated column will be fixed in executor
+			 * virtual generated column stores a null value; stored generated
+			 * column will be fixed in executor
 			 */
 			new_tle = NULL;
 		}
@@ -4358,6 +4361,150 @@ RewriteQuery(Query *parsetree, List *rewrite_events, int orig_rt_length)
 }
 
 
+static Node *
+expand_generated_columns_in_expr_mutator(Node *node, Relation rel)
+{
+	if (node == NULL)
+		return NULL;
+
+	if (IsA(node, Var))
+	{
+		Var		   *v = (Var *) node;
+		AttrNumber	attnum = v->varattno;
+
+		if (attnum > 0 && TupleDescAttr(RelationGetDescr(rel), attnum - 1)->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
+		{
+			node = build_column_default(rel, attnum);
+			if (node == NULL)
+				elog(ERROR, "no generation expression found for column number %d of table \"%s\"",
+					 attnum, RelationGetRelationName(rel));
+			ChangeVarNodes(node, 1, v->varno, 0);
+		}
+
+		return node;
+	}
+	else
+		return expression_tree_mutator(node, expand_generated_columns_in_expr_mutator, rel);
+}
+
+
+Node *
+expand_generated_columns_in_expr(Node *node, Relation rel)
+{
+	TupleDesc	tupdesc = RelationGetDescr(rel);
+
+	if (tupdesc->constr && tupdesc->constr->has_generated_virtual)
+		return expression_tree_mutator(node,
+									   expand_generated_columns_in_expr_mutator,
+									   rel);
+	else
+		return node;
+}
+
+struct expand_generated_context
+{
+	/* list of range tables, innermost last */
+	List	   *rtables;
+};
+
+static Node *
+expand_generated_columns_in_query_mutator(Node *node, struct expand_generated_context *context)
+{
+	if (node == NULL)
+		return NULL;
+
+	if (IsA(node, Var))
+	{
+		Var		   *v = (Var *) node;
+		Oid			relid;
+		AttrNumber	attnum;
+		List	   *rtable = list_nth_node(List,
+										   context->rtables,
+										   list_length(context->rtables) - v->varlevelsup - 1);
+
+		relid = rt_fetch(v->varno, rtable)->relid;
+		attnum = v->varattno;
+
+		if (!relid || !attnum)
+			return node;
+
+		if (get_attgenerated(relid, attnum) == ATTRIBUTE_GENERATED_VIRTUAL)
+		{
+			Relation	rt_entry_relation = table_open(relid, NoLock);
+
+			node = build_column_default(rt_entry_relation, attnum);
+			if (node == NULL)
+				elog(ERROR, "no generation expression found for column number %d of table \"%s\"",
+					 attnum, RelationGetRelationName(rt_entry_relation));
+			ChangeVarNodes(node, 1, v->varno, v->varlevelsup);
+
+			table_close(rt_entry_relation, NoLock);
+		}
+
+		return node;
+	}
+	else if (IsA(node, Query))
+	{
+		Query	   *query = (Query *) node;
+
+		query = expand_generated_columns_in_query(query, context);
+
+		return (Node *) query;
+	}
+	else
+		return expression_tree_mutator(node, expand_generated_columns_in_query_mutator, context);
+}
+
+/*
+ * Expand virtual generated columns in a Query.  We do some optimizations here
+ * to avoid digging through the whole Query unless necessary.
+ */
+static Query *
+expand_generated_columns_in_query(Query *query, struct expand_generated_context *context)
+{
+	context->rtables = lappend(context->rtables, query->rtable);
+
+	/*
+	 * If any table in the query has a virtual column or there is a sublink,
+	 * then we need to do the whole walk.
+	 */
+	if (query->hasGeneratedVirtual || query->hasSubLinks)
+	{
+		query = query_tree_mutator(query,
+								   expand_generated_columns_in_query_mutator,
+								   context,
+								   QTW_DONT_COPY_QUERY);
+	}
+
+	/*
+	 * Else we only need to process subqueries.
+	 */
+	else
+	{
+		ListCell   *lc;
+
+		foreach(lc, query->rtable)
+		{
+			RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc);
+
+			if (rte->rtekind == RTE_SUBQUERY)
+				rte->subquery = expand_generated_columns_in_query(rte->subquery, context);
+		}
+
+		foreach(lc, query->cteList)
+		{
+			CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc);
+
+			cte->ctequery = (Node *) expand_generated_columns_in_query(castNode(Query, cte->ctequery), context);
+		}
+	}
+
+	context->rtables = list_truncate(context->rtables, list_length(context->rtables) - 1);
+
+	return query;
+}
+
+
 /*
  * QueryRewrite -
  *	  Primary entry point to the query rewriter.
@@ -4413,6 +4560,21 @@ QueryRewrite(Query *parsetree)
 	/*
 	 * Step 3
 	 *
+	 * Expand virtual generated columns.
+	 */
+	foreach(l, querylist)
+	{
+		Query	   *query = (Query *) lfirst(l);
+		struct expand_generated_context context;
+
+		context.rtables = NIL;
+
+		query = expand_generated_columns_in_query(query, &context);
+	}
+
+	/*
+	 * Step 4
+	 *
 	 * Determine which, if any, of the resulting queries is supposed to set
 	 * the command-result tag; and update the canSetTag fields accordingly.
 	 *
diff --git a/src/backend/utils/cache/partcache.c b/src/backend/utils/cache/partcache.c
index beec6cddbc4..1dee7c1e899 100644
--- a/src/backend/utils/cache/partcache.c
+++ b/src/backend/utils/cache/partcache.c
@@ -26,6 +26,7 @@
 #include "nodes/nodeFuncs.h"
 #include "optimizer/optimizer.h"
 #include "partitioning/partbounds.h"
+#include "rewrite/rewriteHandler.h"
 #include "utils/builtins.h"
 #include "utils/lsyscache.h"
 #include "utils/memutils.h"
@@ -148,6 +149,8 @@ RelationBuildPartitionKey(Relation relation)
 		expr = stringToNode(exprString);
 		pfree(exprString);
 
+		expr = expand_generated_columns_in_expr(expr, relation);
+
 		/*
 		 * Run the expressions through const-simplification since the planner
 		 * will be comparing them to similarly-processed qual clause operands,
diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index 05c4ae79707..ce6c3712a65 100644
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -588,6 +588,8 @@ RelationBuildTupleDesc(Relation relation)
 			constr->has_not_null = true;
 		if (attp->attgenerated == ATTRIBUTE_GENERATED_STORED)
 			constr->has_generated_stored = true;
+		if (attp->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
+			constr->has_generated_virtual = true;
 		if (attp->atthasdef)
 			ndef++;
 
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 242ebe807f5..4dd52829efe 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -16212,6 +16212,9 @@ dumpTableSchema(Archive *fout, const TableInfo *tbinfo)
 						if (tbinfo->attgenerated[j] == ATTRIBUTE_GENERATED_STORED)
 							appendPQExpBuffer(q, " GENERATED ALWAYS AS (%s) STORED",
 											  tbinfo->attrdefs[j]->adef_expr);
+						else if (tbinfo->attgenerated[j] == ATTRIBUTE_GENERATED_VIRTUAL)
+							appendPQExpBuffer(q, " GENERATED ALWAYS AS (%s)",
+											  tbinfo->attrdefs[j]->adef_expr);
 						else
 							appendPQExpBuffer(q, " DEFAULT %s",
 											  tbinfo->attrdefs[j]->adef_expr);
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index 7085053a2d6..e980829dacc 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -3631,12 +3631,14 @@
 		create_order => 3,
 		create_sql => 'CREATE TABLE dump_test.test_table_generated (
 						   col1 int primary key,
-						   col2 int generated always as (col1 * 2) stored
+						   col2 int generated always as (col1 * 2) stored,
+						   col3 int generated always as (col1 * 3) virtual
 					   );',
 		regexp => qr/^
 			\QCREATE TABLE dump_test.test_table_generated (\E\n
 			\s+\Qcol1 integer CONSTRAINT \E[a-z0-9_]*\Q NOT NULL NO INHERIT,\E\n
-			\s+\Qcol2 integer GENERATED ALWAYS AS ((col1 * 2)) STORED\E\n
+			\s+\Qcol2 integer GENERATED ALWAYS AS ((col1 * 2)) STORED,\E\n
+			\s+\Qcol3 integer GENERATED ALWAYS AS ((col1 * 3))\E\n
 			\);
 			/xms,
 		like =>
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 4a9ee4a54d5..608c0b98fe7 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -2089,6 +2089,12 @@ describeOneTableDetails(const char *schemaname,
 									   PQgetvalue(res, i, attrdef_col));
 				mustfree = true;
 			}
+			else if (generated[0] == ATTRIBUTE_GENERATED_VIRTUAL)
+			{
+				default_str = psprintf("generated always as (%s)",
+									   PQgetvalue(res, i, attrdef_col));
+				mustfree = true;
+			}
 			else
 				default_str = PQgetvalue(res, i, attrdef_col);
 
diff --git a/src/include/access/tupdesc.h b/src/include/access/tupdesc.h
index 8930a28d660..6ef40249583 100644
--- a/src/include/access/tupdesc.h
+++ b/src/include/access/tupdesc.h
@@ -43,6 +43,7 @@ typedef struct TupleConstr
 	uint16		num_check;
 	bool		has_not_null;
 	bool		has_generated_stored;
+	bool		has_generated_virtual;
 } TupleConstr;
 
 /*
diff --git a/src/include/catalog/pg_attribute.h b/src/include/catalog/pg_attribute.h
index 1c62b8bfcb5..8f158dc6083 100644
--- a/src/include/catalog/pg_attribute.h
+++ b/src/include/catalog/pg_attribute.h
@@ -234,6 +234,7 @@ MAKE_SYSCACHE(ATTNUM, pg_attribute_relid_attnum_index, 128);
 #define		  ATTRIBUTE_IDENTITY_BY_DEFAULT 'd'
 
 #define		  ATTRIBUTE_GENERATED_STORED	's'
+#define		  ATTRIBUTE_GENERATED_VIRTUAL	'v'
 
 #endif							/* EXPOSE_TO_CLIENT_CODE */
 
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index af80a5d38e0..ec7b17bcb30 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -160,6 +160,8 @@ typedef struct Query
 	bool		hasForUpdate pg_node_attr(query_jumble_ignore);
 	/* rewriter has applied some RLS policy */
 	bool		hasRowSecurity pg_node_attr(query_jumble_ignore);
+	/* some table has a virtual generated column */
+	bool		hasGeneratedVirtual pg_node_attr(query_jumble_ignore);
 	/* is a RETURN statement */
 	bool		isReturn pg_node_attr(query_jumble_ignore);
 
@@ -2748,6 +2750,7 @@ typedef struct Constraint
 	char	   *cooked_expr;	/* CHECK or DEFAULT expression, as
 								 * nodeToString representation */
 	char		generated_when; /* ALWAYS or BY DEFAULT */
+	char		generated_kind; /* STORED or VIRTUAL */
 	int			inhcount;		/* initial inheritance count to apply, for
 								 * "raw" NOT NULL constraints */
 	bool		nulls_not_distinct; /* null treatment for UNIQUE constraints */
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index f9a4afd4723..1cae2357c28 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -493,6 +493,7 @@ PG_KEYWORD("verbose", VERBOSE, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("version", VERSION_P, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("view", VIEW, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("views", VIEWS, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("virtual", VIRTUAL, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("volatile", VOLATILE, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("when", WHEN, RESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("where", WHERE, RESERVED_KEYWORD, AS_LABEL)
diff --git a/src/include/parser/parse_node.h b/src/include/parser/parse_node.h
index 5b781d87a9d..1b02128548b 100644
--- a/src/include/parser/parse_node.h
+++ b/src/include/parser/parse_node.h
@@ -225,6 +225,7 @@ struct ParseState
 	bool		p_hasTargetSRFs;
 	bool		p_hasSubLinks;
 	bool		p_hasModifyingCTE;
+	bool		p_hasGeneratedVirtual;
 
 	Node	   *p_last_srf;		/* most recent set-returning func/op found */
 
diff --git a/src/include/rewrite/rewriteHandler.h b/src/include/rewrite/rewriteHandler.h
index 1b65cda71cf..a646a20675a 100644
--- a/src/include/rewrite/rewriteHandler.h
+++ b/src/include/rewrite/rewriteHandler.h
@@ -38,4 +38,6 @@ extern void error_view_not_updatable(Relation view,
 									 List *mergeActionList,
 									 const char *detail);
 
+extern Node *expand_generated_columns_in_expr(Node *node, Relation rel);
+
 #endif							/* REWRITEHANDLER_H */
diff --git a/src/pl/plperl/expected/plperl_trigger.out b/src/pl/plperl/expected/plperl_trigger.out
index d4879e2f03b..42c52ecbba8 100644
--- a/src/pl/plperl/expected/plperl_trigger.out
+++ b/src/pl/plperl/expected/plperl_trigger.out
@@ -8,7 +8,8 @@ CREATE TABLE trigger_test (
 );
 CREATE TABLE trigger_test_generated (
     i int,
-    j int GENERATED ALWAYS AS (i * 2) STORED
+    j int GENERATED ALWAYS AS (i * 2) STORED,
+    k int GENERATED ALWAYS AS (i * 3) VIRTUAL
 );
 CREATE OR REPLACE FUNCTION trigger_data() RETURNS trigger LANGUAGE plperl AS $$
 
@@ -386,7 +387,7 @@ INSERT INTO trigger_test_generated (i) VALUES (1);
 ERROR:  cannot set generated column "j"
 CONTEXT:  PL/Perl function "generated_test_func1"
 SELECT * FROM trigger_test_generated;
- i | j 
----+---
+ i | j | k 
+---+---+---
 (0 rows)
 
diff --git a/src/pl/plperl/plperl.c b/src/pl/plperl/plperl.c
index d68ad7be345..9611aa82352 100644
--- a/src/pl/plperl/plperl.c
+++ b/src/pl/plperl/plperl.c
@@ -3052,6 +3052,9 @@ plperl_hash_from_tuple(HeapTuple tuple, TupleDesc tupdesc, bool include_generate
 			/* don't include unless requested */
 			if (!include_generated)
 				continue;
+			/* never include virtual columns */
+			if (att->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
+				continue;
 		}
 
 		attname = NameStr(att->attname);
diff --git a/src/pl/plperl/sql/plperl_trigger.sql b/src/pl/plperl/sql/plperl_trigger.sql
index 4adddeb80ac..2798a02fa12 100644
--- a/src/pl/plperl/sql/plperl_trigger.sql
+++ b/src/pl/plperl/sql/plperl_trigger.sql
@@ -10,7 +10,8 @@ CREATE TABLE trigger_test (
 
 CREATE TABLE trigger_test_generated (
     i int,
-    j int GENERATED ALWAYS AS (i * 2) STORED
+    j int GENERATED ALWAYS AS (i * 2) STORED,
+    k int GENERATED ALWAYS AS (i * 3) VIRTUAL
 );
 
 CREATE OR REPLACE FUNCTION trigger_data() RETURNS trigger LANGUAGE plperl AS $$
diff --git a/src/pl/plpython/expected/plpython_trigger.out b/src/pl/plpython/expected/plpython_trigger.out
index dd1ca32fa49..12f5e15b2a5 100644
--- a/src/pl/plpython/expected/plpython_trigger.out
+++ b/src/pl/plpython/expected/plpython_trigger.out
@@ -69,7 +69,8 @@ CREATE TABLE trigger_test
 	(i int, v text );
 CREATE TABLE trigger_test_generated (
 	i int,
-        j int GENERATED ALWAYS AS (i * 2) STORED
+        j int GENERATED ALWAYS AS (i * 2) STORED,
+        k int GENERATED ALWAYS AS (i * 3) VIRTUAL
 );
 CREATE FUNCTION trigger_data() RETURNS trigger LANGUAGE plpython3u AS $$
 
@@ -614,7 +615,7 @@ ERROR:  cannot set generated column "j"
 CONTEXT:  while modifying trigger row
 PL/Python function "generated_test_func1"
 SELECT * FROM trigger_test_generated;
- i | j 
----+---
+ i | j | k 
+---+---+---
 (0 rows)
 
diff --git a/src/pl/plpython/plpy_typeio.c b/src/pl/plpython/plpy_typeio.c
index db14c5f8dae..51e1d610259 100644
--- a/src/pl/plpython/plpy_typeio.c
+++ b/src/pl/plpython/plpy_typeio.c
@@ -844,6 +844,9 @@ PLyDict_FromTuple(PLyDatumToOb *arg, HeapTuple tuple, TupleDesc desc, bool inclu
 				/* don't include unless requested */
 				if (!include_generated)
 					continue;
+				/* never include virtual columns */
+				if (attr->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
+					continue;
 			}
 
 			key = NameStr(attr->attname);
diff --git a/src/pl/plpython/sql/plpython_trigger.sql b/src/pl/plpython/sql/plpython_trigger.sql
index e5504b9ab1d..d50596a673c 100644
--- a/src/pl/plpython/sql/plpython_trigger.sql
+++ b/src/pl/plpython/sql/plpython_trigger.sql
@@ -69,7 +69,8 @@ CREATE TABLE trigger_test
 
 CREATE TABLE trigger_test_generated (
 	i int,
-        j int GENERATED ALWAYS AS (i * 2) STORED
+        j int GENERATED ALWAYS AS (i * 2) STORED,
+        k int GENERATED ALWAYS AS (i * 3) VIRTUAL
 );
 
 CREATE FUNCTION trigger_data() RETURNS trigger LANGUAGE plpython3u AS $$
diff --git a/src/pl/tcl/expected/pltcl_trigger.out b/src/pl/tcl/expected/pltcl_trigger.out
index 008ea195095..3bf63ba6133 100644
--- a/src/pl/tcl/expected/pltcl_trigger.out
+++ b/src/pl/tcl/expected/pltcl_trigger.out
@@ -63,7 +63,8 @@ CREATE TABLE trigger_test (
 ALTER TABLE trigger_test DROP dropme;
 CREATE TABLE trigger_test_generated (
    i int,
-   j int GENERATED ALWAYS AS (i * 2) STORED
+   j int GENERATED ALWAYS AS (i * 2) STORED,
+   k int GENERATED ALWAYS AS (i * 3) VIRTUAL
 );
 CREATE VIEW trigger_test_view AS SELECT i, v FROM trigger_test;
 CREATE FUNCTION trigger_data() returns trigger language pltcl as $_$
@@ -647,7 +648,7 @@ NOTICE:  OLD: {}
 NOTICE:  TG_level: ROW
 NOTICE:  TG_name: show_trigger_data_trig_before
 NOTICE:  TG_op: INSERT
-NOTICE:  TG_relatts: {{} i j}
+NOTICE:  TG_relatts: {{} i j k}
 NOTICE:  TG_relid: bogus:12345
 NOTICE:  TG_table_name: trigger_test_generated
 NOTICE:  TG_table_schema: public
@@ -658,7 +659,7 @@ NOTICE:  OLD: {}
 NOTICE:  TG_level: ROW
 NOTICE:  TG_name: show_trigger_data_trig_after
 NOTICE:  TG_op: INSERT
-NOTICE:  TG_relatts: {{} i j}
+NOTICE:  TG_relatts: {{} i j k}
 NOTICE:  TG_relid: bogus:12345
 NOTICE:  TG_table_name: trigger_test_generated
 NOTICE:  TG_table_schema: public
@@ -670,7 +671,7 @@ NOTICE:  OLD: {i: 1, j: 2}
 NOTICE:  TG_level: ROW
 NOTICE:  TG_name: show_trigger_data_trig_before
 NOTICE:  TG_op: UPDATE
-NOTICE:  TG_relatts: {{} i j}
+NOTICE:  TG_relatts: {{} i j k}
 NOTICE:  TG_relid: bogus:12345
 NOTICE:  TG_table_name: trigger_test_generated
 NOTICE:  TG_table_schema: public
@@ -681,7 +682,7 @@ NOTICE:  OLD: {i: 1, j: 2}
 NOTICE:  TG_level: ROW
 NOTICE:  TG_name: show_trigger_data_trig_after
 NOTICE:  TG_op: UPDATE
-NOTICE:  TG_relatts: {{} i j}
+NOTICE:  TG_relatts: {{} i j k}
 NOTICE:  TG_relid: bogus:12345
 NOTICE:  TG_table_name: trigger_test_generated
 NOTICE:  TG_table_schema: public
@@ -693,7 +694,7 @@ NOTICE:  OLD: {i: 11, j: 22}
 NOTICE:  TG_level: ROW
 NOTICE:  TG_name: show_trigger_data_trig_before
 NOTICE:  TG_op: DELETE
-NOTICE:  TG_relatts: {{} i j}
+NOTICE:  TG_relatts: {{} i j k}
 NOTICE:  TG_relid: bogus:12345
 NOTICE:  TG_table_name: trigger_test_generated
 NOTICE:  TG_table_schema: public
@@ -704,7 +705,7 @@ NOTICE:  OLD: {i: 11, j: 22}
 NOTICE:  TG_level: ROW
 NOTICE:  TG_name: show_trigger_data_trig_after
 NOTICE:  TG_op: DELETE
-NOTICE:  TG_relatts: {{} i j}
+NOTICE:  TG_relatts: {{} i j k}
 NOTICE:  TG_relid: bogus:12345
 NOTICE:  TG_table_name: trigger_test_generated
 NOTICE:  TG_table_schema: public
@@ -882,7 +883,7 @@ TRUNCATE trigger_test_generated;
 INSERT INTO trigger_test_generated (i) VALUES (1);
 ERROR:  cannot set generated column "j"
 SELECT * FROM trigger_test_generated;
- i | j 
----+---
+ i | j | k 
+---+---+---
 (0 rows)
 
diff --git a/src/pl/tcl/pltcl.c b/src/pl/tcl/pltcl.c
index 18d14a2b982..fc2399fc978 100644
--- a/src/pl/tcl/pltcl.c
+++ b/src/pl/tcl/pltcl.c
@@ -3114,6 +3114,9 @@ pltcl_build_tuple_argument(HeapTuple tuple, TupleDesc tupdesc, bool include_gene
 			/* don't include unless requested */
 			if (!include_generated)
 				continue;
+			/* never include virtual columns */
+			if (att->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
+				continue;
 		}
 
 		/************************************************************
diff --git a/src/pl/tcl/sql/pltcl_trigger.sql b/src/pl/tcl/sql/pltcl_trigger.sql
index 2db75a333a0..e4acf6a5fd9 100644
--- a/src/pl/tcl/sql/pltcl_trigger.sql
+++ b/src/pl/tcl/sql/pltcl_trigger.sql
@@ -73,7 +73,8 @@ CREATE TABLE trigger_test (
 
 CREATE TABLE trigger_test_generated (
    i int,
-   j int GENERATED ALWAYS AS (i * 2) STORED
+   j int GENERATED ALWAYS AS (i * 2) STORED,
+   k int GENERATED ALWAYS AS (i * 3) VIRTUAL
 );
 
 CREATE VIEW trigger_test_view AS SELECT i, v FROM trigger_test;
diff --git a/src/test/regress/expected/create_table_like.out b/src/test/regress/expected/create_table_like.out
index 61956773ffd..9d36904c622 100644
--- a/src/test/regress/expected/create_table_like.out
+++ b/src/test/regress/expected/create_table_like.out
@@ -113,19 +113,20 @@ SELECT * FROM test_like_id_3;  -- identity was copied and applied
 (1 row)
 
 DROP TABLE test_like_id_1, test_like_id_2, test_like_id_3;
-CREATE TABLE test_like_gen_1 (a int, b int GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE test_like_gen_1 (a int, b int GENERATED ALWAYS AS (a * 2) STORED, c int GENERATED ALWAYS AS (a * 3) VIRTUAL);
 \d test_like_gen_1
                         Table "public.test_like_gen_1"
  Column |  Type   | Collation | Nullable |              Default               
 --------+---------+-----------+----------+------------------------------------
  a      | integer |           |          | 
  b      | integer |           |          | generated always as (a * 2) stored
+ c      | integer |           |          | generated always as (a * 3)
 
 INSERT INTO test_like_gen_1 (a) VALUES (1);
 SELECT * FROM test_like_gen_1;
- a | b 
----+---
- 1 | 2
+ a | b | c 
+---+---+---
+ 1 | 2 | 3
 (1 row)
 
 CREATE TABLE test_like_gen_2 (LIKE test_like_gen_1);
@@ -135,12 +136,13 @@ CREATE TABLE test_like_gen_2 (LIKE test_like_gen_1);
 --------+---------+-----------+----------+---------
  a      | integer |           |          | 
  b      | integer |           |          | 
+ c      | integer |           |          | 
 
 INSERT INTO test_like_gen_2 (a) VALUES (1);
 SELECT * FROM test_like_gen_2;
- a | b 
----+---
- 1 |  
+ a | b | c 
+---+---+---
+ 1 |   |  
 (1 row)
 
 CREATE TABLE test_like_gen_3 (LIKE test_like_gen_1 INCLUDING GENERATED);
@@ -150,12 +152,13 @@ CREATE TABLE test_like_gen_3 (LIKE test_like_gen_1 INCLUDING GENERATED);
 --------+---------+-----------+----------+------------------------------------
  a      | integer |           |          | 
  b      | integer |           |          | generated always as (a * 2) stored
+ c      | integer |           |          | generated always as (a * 3)
 
 INSERT INTO test_like_gen_3 (a) VALUES (1);
 SELECT * FROM test_like_gen_3;
- a | b 
----+---
- 1 | 2
+ a | b | c 
+---+---+---
+ 1 | 2 | 3
 (1 row)
 
 DROP TABLE test_like_gen_1, test_like_gen_2, test_like_gen_3;
diff --git a/src/test/regress/expected/generated_stored.out b/src/test/regress/expected/generated_stored.out
index 6682092124c..7d230925f89 100644
--- a/src/test/regress/expected/generated_stored.out
+++ b/src/test/regress/expected/generated_stored.out
@@ -1,5 +1,5 @@
 -- sanity check of system catalog
-SELECT attrelid, attname, attgenerated FROM pg_attribute WHERE attgenerated NOT IN ('', 's');
+SELECT attrelid, attname, attgenerated FROM pg_attribute WHERE attgenerated NOT IN ('', 's', 'v');
  attrelid | attname | attgenerated 
 ----------+---------+--------------
 (0 rows)
diff --git a/src/test/regress/expected/generated_stored.out b/src/test/regress/expected/generated_virtual.out
similarity index 71%
copy from src/test/regress/expected/generated_stored.out
copy to src/test/regress/expected/generated_virtual.out
index 6682092124c..ff27feba435 100644
--- a/src/test/regress/expected/generated_stored.out
+++ b/src/test/regress/expected/generated_virtual.out
@@ -1,15 +1,15 @@
 -- sanity check of system catalog
-SELECT attrelid, attname, attgenerated FROM pg_attribute WHERE attgenerated NOT IN ('', 's');
+SELECT attrelid, attname, attgenerated FROM pg_attribute WHERE attgenerated NOT IN ('', 's', 'v');
  attrelid | attname | attgenerated 
 ----------+---------+--------------
 (0 rows)
 
-CREATE SCHEMA generated_stored_tests;
-GRANT USAGE ON SCHEMA generated_stored_tests TO PUBLIC;
-SET search_path = generated_stored_tests;
-CREATE TABLE gtest0 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (55) STORED);
-CREATE TABLE gtest1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED);
-SELECT table_name, column_name, column_default, is_nullable, is_generated, generation_expression FROM information_schema.columns WHERE table_schema = 'generated_stored_tests' ORDER BY 1, 2;
+CREATE SCHEMA generated_virtual_tests;
+GRANT USAGE ON SCHEMA generated_virtual_tests TO PUBLIC;
+SET search_path = generated_virtual_tests;
+CREATE TABLE gtest0 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (55) VIRTUAL);
+CREATE TABLE gtest1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL);
+SELECT table_name, column_name, column_default, is_nullable, is_generated, generation_expression FROM information_schema.columns WHERE table_schema = 'generated_virtual_tests' ORDER BY 1, 2;
  table_name | column_name | column_default | is_nullable | is_generated | generation_expression 
 ------------+-------------+----------------+-------------+--------------+-----------------------
  gtest0     | a           |                | NO          | NEVER        | 
@@ -18,89 +18,89 @@ SELECT table_name, column_name, column_default, is_nullable, is_generated, gener
  gtest1     | b           |                | YES         | ALWAYS       | (a * 2)
 (4 rows)
 
-SELECT table_name, column_name, dependent_column FROM information_schema.column_column_usage WHERE table_schema = 'generated_stored_tests' ORDER BY 1, 2, 3;
+SELECT table_name, column_name, dependent_column FROM information_schema.column_column_usage WHERE table_schema = 'generated_virtual_tests' ORDER BY 1, 2, 3;
  table_name | column_name | dependent_column 
 ------------+-------------+------------------
  gtest1     | a           | b
 (1 row)
 
 \d gtest1
-                    Table "generated_stored_tests.gtest1"
- Column |  Type   | Collation | Nullable |              Default               
---------+---------+-----------+----------+------------------------------------
+                Table "generated_virtual_tests.gtest1"
+ Column |  Type   | Collation | Nullable |           Default           
+--------+---------+-----------+----------+-----------------------------
  a      | integer |           | not null | 
- b      | integer |           |          | generated always as (a * 2) stored
+ b      | integer |           |          | generated always as (a * 2)
 Indexes:
     "gtest1_pkey" PRIMARY KEY, btree (a)
 
 -- duplicate generated
-CREATE TABLE gtest_err_1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED GENERATED ALWAYS AS (a * 3) STORED);
+CREATE TABLE gtest_err_1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL GENERATED ALWAYS AS (a * 3) VIRTUAL);
 ERROR:  multiple generation clauses specified for column "b" of table "gtest_err_1"
-LINE 1: ...ARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED GENERATED ...
+LINE 1: ...RY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL GENERATED ...
                                                              ^
 -- references to other generated columns, including self-references
-CREATE TABLE gtest_err_2a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (b * 2) STORED);
+CREATE TABLE gtest_err_2a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (b * 2) VIRTUAL);
 ERROR:  cannot use generated column "b" in column generation expression
-LINE 1: ...2a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (b * 2) STO...
+LINE 1: ...2a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (b * 2) VIR...
                                                              ^
 DETAIL:  A generated column cannot reference another generated column.
-CREATE TABLE gtest_err_2b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED, c int GENERATED ALWAYS AS (b * 3) STORED);
+CREATE TABLE gtest_err_2b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL, c int GENERATED ALWAYS AS (b * 3) VIRTUAL);
 ERROR:  cannot use generated column "b" in column generation expression
-LINE 1: ...AYS AS (a * 2) STORED, c int GENERATED ALWAYS AS (b * 3) STO...
+LINE 1: ...YS AS (a * 2) VIRTUAL, c int GENERATED ALWAYS AS (b * 3) VIR...
                                                              ^
 DETAIL:  A generated column cannot reference another generated column.
 -- a whole-row var is a self-reference on steroids, so disallow that too
 CREATE TABLE gtest_err_2c (a int PRIMARY KEY,
-    b int GENERATED ALWAYS AS (num_nulls(gtest_err_2c)) STORED);
+    b int GENERATED ALWAYS AS (num_nulls(gtest_err_2c)) VIRTUAL);
 ERROR:  cannot use whole-row variable in column generation expression
-LINE 2:     b int GENERATED ALWAYS AS (num_nulls(gtest_err_2c)) STOR...
+LINE 2:     b int GENERATED ALWAYS AS (num_nulls(gtest_err_2c)) VIRT...
                                                  ^
 DETAIL:  This would cause the generated column to depend on its own value.
 -- invalid reference
-CREATE TABLE gtest_err_3 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (c * 2) STORED);
+CREATE TABLE gtest_err_3 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (c * 2) VIRTUAL);
 ERROR:  column "c" does not exist
-LINE 1: ..._3 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (c * 2) STO...
+LINE 1: ..._3 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (c * 2) VIR...
                                                              ^
 -- generation expression must be immutable
-CREATE TABLE gtest_err_4 (a int PRIMARY KEY, b double precision GENERATED ALWAYS AS (random()) STORED);
+CREATE TABLE gtest_err_4 (a int PRIMARY KEY, b double precision GENERATED ALWAYS AS (random()) VIRTUAL);
 ERROR:  generation expression is not immutable
 -- ... but be sure that the immutability test is accurate
-CREATE TABLE gtest2 (a int, b text GENERATED ALWAYS AS (a || ' sec') STORED);
+CREATE TABLE gtest2 (a int, b text GENERATED ALWAYS AS (a || ' sec') VIRTUAL);
 DROP TABLE gtest2;
 -- cannot have default/identity and generated
-CREATE TABLE gtest_err_5a (a int PRIMARY KEY, b int DEFAULT 5 GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE gtest_err_5a (a int PRIMARY KEY, b int DEFAULT 5 GENERATED ALWAYS AS (a * 2) VIRTUAL);
 ERROR:  both default and generation expression specified for column "b" of table "gtest_err_5a"
 LINE 1: ... gtest_err_5a (a int PRIMARY KEY, b int DEFAULT 5 GENERATED ...
                                                              ^
-CREATE TABLE gtest_err_5b (a int PRIMARY KEY, b int GENERATED ALWAYS AS identity GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE gtest_err_5b (a int PRIMARY KEY, b int GENERATED ALWAYS AS identity GENERATED ALWAYS AS (a * 2) VIRTUAL);
 ERROR:  both identity and generation expression specified for column "b" of table "gtest_err_5b"
 LINE 1: ...t PRIMARY KEY, b int GENERATED ALWAYS AS identity GENERATED ...
                                                              ^
 -- reference to system column not allowed in generated column
 -- (except tableoid, which we test below)
-CREATE TABLE gtest_err_6a (a int PRIMARY KEY, b bool GENERATED ALWAYS AS (xmin <> 37) STORED);
+CREATE TABLE gtest_err_6a (a int PRIMARY KEY, b bool GENERATED ALWAYS AS (xmin <> 37) VIRTUAL);
 ERROR:  cannot use system column "xmin" in column generation expression
 LINE 1: ...a (a int PRIMARY KEY, b bool GENERATED ALWAYS AS (xmin <> 37...
                                                              ^
 -- various prohibited constructs
-CREATE TABLE gtest_err_7a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (avg(a)) STORED);
+CREATE TABLE gtest_err_7a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (avg(a)) VIRTUAL);
 ERROR:  aggregate functions are not allowed in column generation expressions
-LINE 1: ...7a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (avg(a)) ST...
+LINE 1: ...7a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (avg(a)) VI...
                                                              ^
-CREATE TABLE gtest_err_7b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (row_number() OVER (ORDER BY a)) STORED);
+CREATE TABLE gtest_err_7b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (row_number() OVER (ORDER BY a)) VIRTUAL);
 ERROR:  window functions are not allowed in column generation expressions
 LINE 1: ...7b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (row_number...
                                                              ^
-CREATE TABLE gtest_err_7c (a int PRIMARY KEY, b int GENERATED ALWAYS AS ((SELECT a)) STORED);
+CREATE TABLE gtest_err_7c (a int PRIMARY KEY, b int GENERATED ALWAYS AS ((SELECT a)) VIRTUAL);
 ERROR:  cannot use subquery in column generation expression
 LINE 1: ...7c (a int PRIMARY KEY, b int GENERATED ALWAYS AS ((SELECT a)...
                                                              ^
-CREATE TABLE gtest_err_7d (a int PRIMARY KEY, b int GENERATED ALWAYS AS (generate_series(1, a)) STORED);
+CREATE TABLE gtest_err_7d (a int PRIMARY KEY, b int GENERATED ALWAYS AS (generate_series(1, a)) VIRTUAL);
 ERROR:  set-returning functions are not allowed in column generation expressions
 LINE 1: ...7d (a int PRIMARY KEY, b int GENERATED ALWAYS AS (generate_s...
                                                              ^
 -- GENERATED BY DEFAULT not allowed
-CREATE TABLE gtest_err_8 (a int PRIMARY KEY, b int GENERATED BY DEFAULT AS (a * 2) STORED);
+CREATE TABLE gtest_err_8 (a int PRIMARY KEY, b int GENERATED BY DEFAULT AS (a * 2) VIRTUAL);
 ERROR:  for a generated column, GENERATED ALWAYS must be specified
 LINE 1: ...E gtest_err_8 (a int PRIMARY KEY, b int GENERATED BY DEFAULT...
                                                              ^
@@ -153,16 +153,10 @@ SELECT a, b FROM gtest1 WHERE b = 4 ORDER BY a;
  2 | 4
 (1 row)
 
--- test that overflow error happens on write
+-- test that overflow error happens on read
 INSERT INTO gtest1 VALUES (2000000000);
-ERROR:  integer out of range
 SELECT * FROM gtest1;
- a | b 
----+---
- 2 | 4
- 1 | 2
-(2 rows)
-
+ERROR:  integer out of range
 DELETE FROM gtest1 WHERE a = 2000000000;
 -- test with joins
 CREATE TABLE gtestx (x int, y int);
@@ -203,8 +197,8 @@ CREATE TABLE gtestm (
   id int PRIMARY KEY,
   f1 int,
   f2 int,
-  f3 int GENERATED ALWAYS AS (f1 * 2) STORED,
-  f4 int GENERATED ALWAYS AS (f2 * 2) STORED
+  f3 int GENERATED ALWAYS AS (f1 * 2) VIRTUAL,
+  f4 int GENERATED ALWAYS AS (f2 * 2) VIRTUAL
 );
 INSERT INTO gtestm VALUES (1, 5, 100);
 MERGE INTO gtestm t USING (VALUES (1, 10), (2, 20)) v(id, f1) ON t.id = v.id
@@ -273,11 +267,11 @@ SELECT * FROM gtest1_1;
 (0 rows)
 
 \d gtest1_1
-                   Table "generated_stored_tests.gtest1_1"
- Column |  Type   | Collation | Nullable |              Default               
---------+---------+-----------+----------+------------------------------------
+               Table "generated_virtual_tests.gtest1_1"
+ Column |  Type   | Collation | Nullable |           Default           
+--------+---------+-----------+----------+-----------------------------
  a      | integer |           | not null | 
- b      | integer |           |          | generated always as (a * 2) stored
+ b      | integer |           |          | generated always as (a * 2)
 Inherits: gtest1
 
 INSERT INTO gtest1_1 VALUES (4);
@@ -296,12 +290,12 @@ SELECT * FROM gtest1;
 
 -- can't have generated column that is a child of normal column
 CREATE TABLE gtest_normal (a int, b int);
-CREATE TABLE gtest_normal_child (a int, b int GENERATED ALWAYS AS (a * 2) STORED) INHERITS (gtest_normal);  -- error
+CREATE TABLE gtest_normal_child (a int, b int GENERATED ALWAYS AS (a * 2) VIRTUAL) INHERITS (gtest_normal);  -- error
 NOTICE:  merging column "a" with inherited definition
 NOTICE:  merging column "b" with inherited definition
 ERROR:  child column "b" specifies generation expression
 HINT:  A child table column cannot be generated unless its parent column is.
-CREATE TABLE gtest_normal_child (a int, b int GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE gtest_normal_child (a int, b int GENERATED ALWAYS AS (a * 2) VIRTUAL);
 ALTER TABLE gtest_normal_child INHERIT gtest_normal;  -- error
 ERROR:  column "b" in child table must not be a generated column
 DROP TABLE gtest_normal, gtest_normal_child;
@@ -312,15 +306,15 @@ ERROR:  column "b" inherits from generated column but specifies default
 CREATE TABLE gtestx (x int, b int GENERATED ALWAYS AS IDENTITY) INHERITS (gtest1);  -- error
 NOTICE:  merging column "b" with inherited definition
 ERROR:  column "b" inherits from generated column but specifies identity
-CREATE TABLE gtestx (x int, b int GENERATED ALWAYS AS (a * 22) STORED) INHERITS (gtest1);  -- ok, overrides parent
+CREATE TABLE gtestx (x int, b int GENERATED ALWAYS AS (a * 22) VIRTUAL) INHERITS (gtest1);  -- ok, overrides parent
 NOTICE:  merging column "b" with inherited definition
 \d+ gtestx
-                                        Table "generated_stored_tests.gtestx"
- Column |  Type   | Collation | Nullable |               Default               | Storage | Stats target | Description 
---------+---------+-----------+----------+-------------------------------------+---------+--------------+-------------
- a      | integer |           | not null |                                     | plain   |              | 
- b      | integer |           |          | generated always as (a * 22) stored | plain   |              | 
- x      | integer |           |          |                                     | plain   |              | 
+                                    Table "generated_virtual_tests.gtestx"
+ Column |  Type   | Collation | Nullable |           Default            | Storage | Stats target | Description 
+--------+---------+-----------+----------+------------------------------+---------+--------------+-------------
+ a      | integer |           | not null |                              | plain   |              | 
+ b      | integer |           |          | generated always as (a * 22) | plain   |              | 
+ x      | integer |           |          |                              | plain   |              | 
 Not-null constraints:
     "gtestx_a_not_null" NOT NULL "a" (inherited)
 Inherits: gtest1
@@ -328,9 +322,9 @@ Inherits: gtest1
 CREATE TABLE gtestxx_1 (a int NOT NULL, b int);
 ALTER TABLE gtestxx_1 INHERIT gtest1;  -- error
 ERROR:  column "b" in child table must be a generated column
-CREATE TABLE gtestxx_3 (a int NOT NULL, b int GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE gtestxx_3 (a int NOT NULL, b int GENERATED ALWAYS AS (a * 2) VIRTUAL);
 ALTER TABLE gtestxx_3 INHERIT gtest1;  -- ok
-CREATE TABLE gtestxx_4 (b int GENERATED ALWAYS AS (a * 2) STORED, a int NOT NULL);
+CREATE TABLE gtestxx_4 (b int GENERATED ALWAYS AS (a * 2) VIRTUAL, a int NOT NULL);
 ALTER TABLE gtestxx_4 INHERIT gtest1;  -- ok
 -- test multiple inheritance mismatches
 CREATE TABLE gtesty (x int, b int DEFAULT 55);
@@ -343,28 +337,28 @@ CREATE TABLE gtest1_y () INHERITS (gtest1, gtesty);  -- error
 NOTICE:  merging multiple inherited definitions of column "b"
 ERROR:  inherited column "b" has a generation conflict
 DROP TABLE gtesty;
-CREATE TABLE gtesty (x int, b int GENERATED ALWAYS AS (x * 22) STORED);
+CREATE TABLE gtesty (x int, b int GENERATED ALWAYS AS (x * 22) VIRTUAL);
 CREATE TABLE gtest1_y () INHERITS (gtest1, gtesty);  -- error
 NOTICE:  merging multiple inherited definitions of column "b"
 ERROR:  column "b" inherits conflicting generation expressions
 HINT:  To resolve the conflict, specify a generation expression explicitly.
-CREATE TABLE gtest1_y (b int GENERATED ALWAYS AS (x + 1) STORED) INHERITS (gtest1, gtesty);  -- ok
+CREATE TABLE gtest1_y (b int GENERATED ALWAYS AS (x + 1) VIRTUAL) INHERITS (gtest1, gtesty);  -- ok
 NOTICE:  merging multiple inherited definitions of column "b"
 NOTICE:  moving and merging column "b" with inherited definition
 DETAIL:  User-specified column moved to the position of the inherited column.
 \d gtest1_y
-                   Table "generated_stored_tests.gtest1_y"
- Column |  Type   | Collation | Nullable |              Default               
---------+---------+-----------+----------+------------------------------------
+               Table "generated_virtual_tests.gtest1_y"
+ Column |  Type   | Collation | Nullable |           Default           
+--------+---------+-----------+----------+-----------------------------
  a      | integer |           | not null | 
- b      | integer |           |          | generated always as (x + 1) stored
+ b      | integer |           |          | generated always as (x + 1)
  x      | integer |           |          | 
 Inherits: gtest1,
           gtesty
 
 -- test correct handling of GENERATED column that's only in child
 CREATE TABLE gtestp (f1 int);
-CREATE TABLE gtestc (f2 int GENERATED ALWAYS AS (f1+1) STORED) INHERITS(gtestp);
+CREATE TABLE gtestc (f2 int GENERATED ALWAYS AS (f1+1) VIRTUAL) INHERITS(gtestp);
 INSERT INTO gtestc values(42);
 TABLE gtestc;
  f1 | f2 
@@ -381,8 +375,8 @@ TABLE gtestc;
 
 DROP TABLE gtestp CASCADE;
 NOTICE:  drop cascades to table gtestc
--- test stored update
-CREATE TABLE gtest3 (a int, b int GENERATED ALWAYS AS (a * 3) STORED);
+-- test update XXX
+CREATE TABLE gtest3 (a int, b int GENERATED ALWAYS AS (a * 3) VIRTUAL);
 INSERT INTO gtest3 (a) VALUES (1), (2), (3), (NULL);
 SELECT * FROM gtest3 ORDER BY a;
  a | b 
@@ -403,7 +397,7 @@ SELECT * FROM gtest3 ORDER BY a;
     |   
 (4 rows)
 
-CREATE TABLE gtest3a (a text, b text GENERATED ALWAYS AS (a || '+' || a) STORED);
+CREATE TABLE gtest3a (a text, b text GENERATED ALWAYS AS (a || '+' || a) VIRTUAL);
 INSERT INTO gtest3a (a) VALUES ('a'), ('b'), ('c'), (NULL);
 SELECT * FROM gtest3a ORDER BY a;
  a |  b  
@@ -468,7 +462,7 @@ SELECT * FROM gtest3 ORDER BY a;
 (4 rows)
 
 -- null values
-CREATE TABLE gtest2 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (NULL) STORED);
+CREATE TABLE gtest2 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (NULL) VIRTUAL);
 INSERT INTO gtest2 VALUES (1);
 SELECT * FROM gtest2;
  a | b 
@@ -477,7 +471,7 @@ SELECT * FROM gtest2;
 (1 row)
 
 -- simple column reference for varlena types
-CREATE TABLE gtest_varlena (a varchar, b varchar GENERATED ALWAYS AS (a) STORED);
+CREATE TABLE gtest_varlena (a varchar, b varchar GENERATED ALWAYS AS (a) VIRTUAL);
 INSERT INTO gtest_varlena (a) VALUES('01234567890123456789');
 INSERT INTO gtest_varlena (a) VALUES(NULL);
 SELECT * FROM gtest_varlena ORDER BY a;
@@ -492,7 +486,7 @@ DROP TABLE gtest_varlena;
 CREATE TYPE double_int as (a int, b int);
 CREATE TABLE gtest4 (
     a int,
-    b double_int GENERATED ALWAYS AS ((a * 2, a * 3)) STORED
+    b double_int GENERATED ALWAYS AS ((a * 2, a * 3)) VIRTUAL
 );
 INSERT INTO gtest4 VALUES (1), (6);
 SELECT * FROM gtest4;
@@ -507,11 +501,11 @@ DROP TYPE double_int;
 -- using tableoid is allowed
 CREATE TABLE gtest_tableoid (
   a int PRIMARY KEY,
-  b bool GENERATED ALWAYS AS (tableoid = 'gtest_tableoid'::regclass) STORED
+  b bool GENERATED ALWAYS AS (tableoid = 'gtest_tableoid'::regclass) VIRTUAL
 );
 INSERT INTO gtest_tableoid VALUES (1), (2);
 ALTER TABLE gtest_tableoid ADD COLUMN
-  c regclass GENERATED ALWAYS AS (tableoid) STORED;
+  c regclass GENERATED ALWAYS AS (tableoid) VIRTUAL;
 SELECT * FROM gtest_tableoid;
  a | b |       c        
 ---+---+----------------
@@ -520,7 +514,7 @@ SELECT * FROM gtest_tableoid;
 (2 rows)
 
 -- drop column behavior
-CREATE TABLE gtest10 (a int PRIMARY KEY, b int, c int GENERATED ALWAYS AS (b * 2) STORED);
+CREATE TABLE gtest10 (a int PRIMARY KEY, b int, c int GENERATED ALWAYS AS (b * 2) VIRTUAL);
 ALTER TABLE gtest10 DROP COLUMN b;  -- fails
 ERROR:  cannot drop column b of table gtest10 because other objects depend on it
 DETAIL:  column c of table gtest10 depends on column b of table gtest10
@@ -528,30 +522,31 @@ HINT:  Use DROP ... CASCADE to drop the dependent objects too.
 ALTER TABLE gtest10 DROP COLUMN b CASCADE;  -- drops c too
 NOTICE:  drop cascades to column c of table gtest10
 \d gtest10
-      Table "generated_stored_tests.gtest10"
+      Table "generated_virtual_tests.gtest10"
  Column |  Type   | Collation | Nullable | Default 
 --------+---------+-----------+----------+---------
  a      | integer |           | not null | 
 Indexes:
     "gtest10_pkey" PRIMARY KEY, btree (a)
 
-CREATE TABLE gtest10a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE gtest10a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL);
 ALTER TABLE gtest10a DROP COLUMN b;
 INSERT INTO gtest10a (a) VALUES (1);
 -- privileges
 CREATE USER regress_user11;
-CREATE TABLE gtest11s (a int PRIMARY KEY, b int, c int GENERATED ALWAYS AS (b * 2) STORED);
-INSERT INTO gtest11s VALUES (1, 10), (2, 20);
-GRANT SELECT (a, c) ON gtest11s TO regress_user11;
+CREATE TABLE gtest11v (a int PRIMARY KEY, b int, c int GENERATED ALWAYS AS (b * 2) VIRTUAL);
+INSERT INTO gtest11v VALUES (1, 10), (2, 20);
+GRANT SELECT (a, c) ON gtest11v TO regress_user11;
 CREATE FUNCTION gf1(a int) RETURNS int AS $$ SELECT a * 3 $$ IMMUTABLE LANGUAGE SQL;
 REVOKE ALL ON FUNCTION gf1(int) FROM PUBLIC;
-CREATE TABLE gtest12s (a int PRIMARY KEY, b int, c int GENERATED ALWAYS AS (gf1(b)) STORED);
-INSERT INTO gtest12s VALUES (1, 10), (2, 20);
+CREATE TABLE gtest12v (a int PRIMARY KEY, b int, c int GENERATED ALWAYS AS (gf1(b)) VIRTUAL);
+INSERT INTO gtest12v VALUES (1, 10), (2, 20);
 GRANT SELECT (a, c) ON gtest12s TO regress_user11;
+ERROR:  relation "gtest12s" does not exist
 SET ROLE regress_user11;
-SELECT a, b FROM gtest11s;  -- not allowed
-ERROR:  permission denied for table gtest11s
-SELECT a, c FROM gtest11s;  -- allowed
+SELECT a, b FROM gtest11v;  -- not allowed
+ERROR:  permission denied for table gtest11v
+SELECT a, c FROM gtest11v;  -- allowed
  a | c  
 ---+----
  1 | 20
@@ -560,231 +555,139 @@ SELECT a, c FROM gtest11s;  -- allowed
 
 SELECT gf1(10);  -- not allowed
 ERROR:  permission denied for function gf1
-SELECT a, c FROM gtest12s;  -- allowed
- a | c  
----+----
- 1 | 30
- 2 | 60
-(2 rows)
-
+SELECT a, c FROM gtest12v;  -- not allowed; TODO: ought to be allowed
+ERROR:  permission denied for table gtest12v
 RESET ROLE;
 DROP FUNCTION gf1(int);  -- fail
 ERROR:  cannot drop function gf1(integer) because other objects depend on it
-DETAIL:  column c of table gtest12s depends on function gf1(integer)
+DETAIL:  column c of table gtest12v depends on function gf1(integer)
 HINT:  Use DROP ... CASCADE to drop the dependent objects too.
-DROP TABLE gtest11s, gtest12s;
+DROP TABLE gtest11v, gtest12v;
 DROP FUNCTION gf1(int);
 DROP USER regress_user11;
 -- check constraints
-CREATE TABLE gtest20 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED CHECK (b < 50));
+CREATE TABLE gtest20 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL CHECK (b < 50));
 INSERT INTO gtest20 (a) VALUES (10);  -- ok
 INSERT INTO gtest20 (a) VALUES (30);  -- violates constraint
 ERROR:  new row for relation "gtest20" violates check constraint "gtest20_b_check"
-DETAIL:  Failing row contains (30, 60).
+DETAIL:  Failing row contains (30).
 ALTER TABLE gtest20 ALTER COLUMN b SET EXPRESSION AS (a * 100);  -- violates constraint
-ERROR:  check constraint "gtest20_b_check" of relation "gtest20" is violated by some row
+ERROR:  column "b" of relation "gtest20" is not a generated column
 ALTER TABLE gtest20 ALTER COLUMN b SET EXPRESSION AS (a * 3);  -- ok
-CREATE TABLE gtest20a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED);
+ERROR:  column "b" of relation "gtest20" is not a generated column
+CREATE TABLE gtest20a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL);
 INSERT INTO gtest20a (a) VALUES (10);
 INSERT INTO gtest20a (a) VALUES (30);
 ALTER TABLE gtest20a ADD CHECK (b < 50);  -- fails on existing row
 ERROR:  check constraint "gtest20a_b_check" of relation "gtest20a" is violated by some row
-CREATE TABLE gtest20b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE gtest20b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL);
 INSERT INTO gtest20b (a) VALUES (10);
 INSERT INTO gtest20b (a) VALUES (30);
 ALTER TABLE gtest20b ADD CONSTRAINT chk CHECK (b < 50) NOT VALID;
 ALTER TABLE gtest20b VALIDATE CONSTRAINT chk;  -- fails on existing row
 ERROR:  check constraint "chk" of relation "gtest20b" is violated by some row
 -- not-null constraints
-CREATE TABLE gtest21a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (nullif(a, 0)) STORED NOT NULL);
+CREATE TABLE gtest21a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (nullif(a, 0)) VIRTUAL NOT NULL);
 INSERT INTO gtest21a (a) VALUES (1);  -- ok
+ERROR:  null value in column "b" of relation "gtest21a" violates not-null constraint
+DETAIL:  Failing row contains (1).
 INSERT INTO gtest21a (a) VALUES (0);  -- violates constraint
 ERROR:  null value in column "b" of relation "gtest21a" violates not-null constraint
-DETAIL:  Failing row contains (0, null).
-CREATE TABLE gtest21b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (nullif(a, 0)) STORED);
-ALTER TABLE gtest21b ALTER COLUMN b SET NOT NULL;
+DETAIL:  Failing row contains (0).
+CREATE TABLE gtest21b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (nullif(a, 0)) VIRTUAL);
+ALTER TABLE gtest21b ALTER COLUMN b SET NOT NULL;  -- FIXME
 INSERT INTO gtest21b (a) VALUES (1);  -- ok
+ERROR:  null value in column "b" of relation "gtest21b" violates not-null constraint
+DETAIL:  Failing row contains (1).
 INSERT INTO gtest21b (a) VALUES (0);  -- violates constraint
 ERROR:  null value in column "b" of relation "gtest21b" violates not-null constraint
-DETAIL:  Failing row contains (0, null).
-ALTER TABLE gtest21b ALTER COLUMN b DROP NOT NULL;
+DETAIL:  Failing row contains (0).
+ALTER TABLE gtest21b ALTER COLUMN b DROP NOT NULL;  -- FIXME
 INSERT INTO gtest21b (a) VALUES (0);  -- ok now
 -- index constraints
-CREATE TABLE gtest22a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a / 2) STORED UNIQUE);
-INSERT INTO gtest22a VALUES (2);
-INSERT INTO gtest22a VALUES (3);
-ERROR:  duplicate key value violates unique constraint "gtest22a_b_key"
-DETAIL:  Key (b)=(1) already exists.
-INSERT INTO gtest22a VALUES (4);
-CREATE TABLE gtest22b (a int, b int GENERATED ALWAYS AS (a / 2) STORED, PRIMARY KEY (a, b));
-INSERT INTO gtest22b VALUES (2);
-INSERT INTO gtest22b VALUES (2);
-ERROR:  duplicate key value violates unique constraint "gtest22b_pkey"
-DETAIL:  Key (a, b)=(2, 1) already exists.
+CREATE TABLE gtest22a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a / 2) VIRTUAL UNIQUE);
+ERROR:  index creation on virtual generated columns is not supported
+--INSERT INTO gtest22a VALUES (2);
+--INSERT INTO gtest22a VALUES (3);
+--INSERT INTO gtest22a VALUES (4);
+CREATE TABLE gtest22b (a int, b int GENERATED ALWAYS AS (a / 2) VIRTUAL, PRIMARY KEY (a, b));
+ERROR:  index creation on virtual generated columns is not supported
+--INSERT INTO gtest22b VALUES (2);
+--INSERT INTO gtest22b VALUES (2);
 -- indexes
-CREATE TABLE gtest22c (a int, b int GENERATED ALWAYS AS (a * 2) STORED);
-CREATE INDEX gtest22c_b_idx ON gtest22c (b);
-CREATE INDEX gtest22c_expr_idx ON gtest22c ((b * 3));
-CREATE INDEX gtest22c_pred_idx ON gtest22c (a) WHERE b > 0;
-\d gtest22c
-                   Table "generated_stored_tests.gtest22c"
- Column |  Type   | Collation | Nullable |              Default               
---------+---------+-----------+----------+------------------------------------
- a      | integer |           |          | 
- b      | integer |           |          | generated always as (a * 2) stored
-Indexes:
-    "gtest22c_b_idx" btree (b)
-    "gtest22c_expr_idx" btree ((b * 3))
-    "gtest22c_pred_idx" btree (a) WHERE b > 0
-
-INSERT INTO gtest22c VALUES (1), (2), (3);
-SET enable_seqscan TO off;
-SET enable_bitmapscan TO off;
-EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b = 4;
-                 QUERY PLAN                  
----------------------------------------------
- Index Scan using gtest22c_b_idx on gtest22c
-   Index Cond: (b = 4)
-(2 rows)
-
-SELECT * FROM gtest22c WHERE b = 4;
- a | b 
----+---
- 2 | 4
-(1 row)
-
-EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b * 3 = 6;
-                   QUERY PLAN                   
-------------------------------------------------
- Index Scan using gtest22c_expr_idx on gtest22c
-   Index Cond: ((b * 3) = 6)
-(2 rows)
-
-SELECT * FROM gtest22c WHERE b * 3 = 6;
- a | b 
----+---
- 1 | 2
-(1 row)
-
-EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
-                   QUERY PLAN                   
-------------------------------------------------
- Index Scan using gtest22c_pred_idx on gtest22c
-   Index Cond: (a = 1)
-(2 rows)
-
-SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
- a | b 
----+---
- 1 | 2
-(1 row)
-
-ALTER TABLE gtest22c ALTER COLUMN b SET EXPRESSION AS (a * 4);
-ANALYZE gtest22c;
-EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b = 8;
-                 QUERY PLAN                  
----------------------------------------------
- Index Scan using gtest22c_b_idx on gtest22c
-   Index Cond: (b = 8)
-(2 rows)
-
-SELECT * FROM gtest22c WHERE b = 8;
- a | b 
----+---
- 2 | 8
-(1 row)
-
-EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b * 3 = 12;
-                   QUERY PLAN                   
-------------------------------------------------
- Index Scan using gtest22c_expr_idx on gtest22c
-   Index Cond: ((b * 3) = 12)
-(2 rows)
-
-SELECT * FROM gtest22c WHERE b * 3 = 12;
- a | b 
----+---
- 1 | 4
-(1 row)
-
-EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
-                   QUERY PLAN                   
-------------------------------------------------
- Index Scan using gtest22c_pred_idx on gtest22c
-   Index Cond: (a = 1)
-(2 rows)
-
-SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
- a | b 
----+---
- 1 | 4
-(1 row)
-
-RESET enable_seqscan;
-RESET enable_bitmapscan;
+CREATE TABLE gtest22c (a int, b int GENERATED ALWAYS AS (a * 2) VIRTUAL);
+--CREATE INDEX gtest22c_b_idx ON gtest22c (b);
+--CREATE INDEX gtest22c_expr_idx ON gtest22c ((b * 3));
+--CREATE INDEX gtest22c_pred_idx ON gtest22c (a) WHERE b > 0;
+--\d gtest22c
+--INSERT INTO gtest22c VALUES (1), (2), (3);
+--SET enable_seqscan TO off;
+--SET enable_bitmapscan TO off;
+--EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b = 4;
+--SELECT * FROM gtest22c WHERE b = 4;
+--EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b * 3 = 6;
+--SELECT * FROM gtest22c WHERE b * 3 = 6;
+--EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
+--SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
+--ALTER TABLE gtest22c ALTER COLUMN b SET EXPRESSION AS (a * 4);
+--ANALYZE gtest22c;
+--EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b = 8;
+--SELECT * FROM gtest22c WHERE b = 8;
+--EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b * 3 = 12;
+--SELECT * FROM gtest22c WHERE b * 3 = 12;
+--EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
+--SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
+--RESET enable_seqscan;
+--RESET enable_bitmapscan;
 -- foreign keys
 CREATE TABLE gtest23a (x int PRIMARY KEY, y int);
-INSERT INTO gtest23a VALUES (1, 11), (2, 22), (3, 33);
-CREATE TABLE gtest23x (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED REFERENCES gtest23a (x) ON UPDATE CASCADE);  -- error
+--INSERT INTO gtest23a VALUES (1, 11), (2, 22), (3, 33);
+CREATE TABLE gtest23x (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL REFERENCES gtest23a (x) ON UPDATE CASCADE);  -- error
 ERROR:  invalid ON UPDATE action for foreign key constraint containing generated column
-CREATE TABLE gtest23x (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED REFERENCES gtest23a (x) ON DELETE SET NULL);  -- error
+CREATE TABLE gtest23x (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL REFERENCES gtest23a (x) ON DELETE SET NULL);  -- error
 ERROR:  invalid ON DELETE action for foreign key constraint containing generated column
-CREATE TABLE gtest23b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED REFERENCES gtest23a (x));
-\d gtest23b
-                   Table "generated_stored_tests.gtest23b"
- Column |  Type   | Collation | Nullable |              Default               
---------+---------+-----------+----------+------------------------------------
- a      | integer |           | not null | 
- b      | integer |           |          | generated always as (a * 2) stored
-Indexes:
-    "gtest23b_pkey" PRIMARY KEY, btree (a)
-Foreign-key constraints:
-    "gtest23b_b_fkey" FOREIGN KEY (b) REFERENCES gtest23a(x)
-
-INSERT INTO gtest23b VALUES (1);  -- ok
-INSERT INTO gtest23b VALUES (5);  -- error
-ERROR:  insert or update on table "gtest23b" violates foreign key constraint "gtest23b_b_fkey"
-DETAIL:  Key (b)=(10) is not present in table "gtest23a".
-ALTER TABLE gtest23b ALTER COLUMN b SET EXPRESSION AS (a * 5); -- error
-ERROR:  insert or update on table "gtest23b" violates foreign key constraint "gtest23b_b_fkey"
-DETAIL:  Key (b)=(5) is not present in table "gtest23a".
-ALTER TABLE gtest23b ALTER COLUMN b SET EXPRESSION AS (a * 1); -- ok
-DROP TABLE gtest23b;
-DROP TABLE gtest23a;
-CREATE TABLE gtest23p (x int, y int GENERATED ALWAYS AS (x * 2) STORED, PRIMARY KEY (y));
-INSERT INTO gtest23p VALUES (1), (2), (3);
+CREATE TABLE gtest23b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL REFERENCES gtest23a (x));
+ERROR:  foreign key constraints on virtual generated columns are not supported
+--\d gtest23b
+--INSERT INTO gtest23b VALUES (1);  -- ok
+--INSERT INTO gtest23b VALUES (5);  -- error
+--ALTER TABLE gtest23b ALTER COLUMN b SET EXPRESSION AS (a * 5); -- error
+--ALTER TABLE gtest23b ALTER COLUMN b SET EXPRESSION AS (a * 1); -- ok
+--DROP TABLE gtest23b;
+--DROP TABLE gtest23a;
+CREATE TABLE gtest23p (x int, y int GENERATED ALWAYS AS (x * 2) VIRTUAL, PRIMARY KEY (y));
+ERROR:  index creation on virtual generated columns is not supported
+--INSERT INTO gtest23p VALUES (1), (2), (3);
 CREATE TABLE gtest23q (a int PRIMARY KEY, b int REFERENCES gtest23p (y));
-INSERT INTO gtest23q VALUES (1, 2);  -- ok
-INSERT INTO gtest23q VALUES (2, 5);  -- error
-ERROR:  insert or update on table "gtest23q" violates foreign key constraint "gtest23q_b_fkey"
-DETAIL:  Key (b)=(5) is not present in table "gtest23p".
+ERROR:  relation "gtest23p" does not exist
+--INSERT INTO gtest23q VALUES (1, 2);  -- ok
+--INSERT INTO gtest23q VALUES (2, 5);  -- error
 -- domains
 CREATE DOMAIN gtestdomain1 AS int CHECK (VALUE < 10);
-CREATE TABLE gtest24 (a int PRIMARY KEY, b gtestdomain1 GENERATED ALWAYS AS (a * 2) STORED);
-INSERT INTO gtest24 (a) VALUES (4);  -- ok
-INSERT INTO gtest24 (a) VALUES (6);  -- error
-ERROR:  value for domain gtestdomain1 violates check constraint "gtestdomain1_check"
+CREATE TABLE gtest24 (a int PRIMARY KEY, b gtestdomain1 GENERATED ALWAYS AS (a * 2) VIRTUAL);
+--INSERT INTO gtest24 (a) VALUES (4);  -- ok
+--INSERT INTO gtest24 (a) VALUES (6);  -- error
 -- typed tables (currently not supported)
 CREATE TYPE gtest_type AS (f1 integer, f2 text, f3 bigint);
-CREATE TABLE gtest28 OF gtest_type (f1 WITH OPTIONS GENERATED ALWAYS AS (f2 *2) STORED);
+CREATE TABLE gtest28 OF gtest_type (f1 WITH OPTIONS GENERATED ALWAYS AS (f2 *2) VIRTUAL);
 ERROR:  generated columns are not supported on typed tables
 DROP TYPE gtest_type CASCADE;
 -- partitioning cases
 CREATE TABLE gtest_parent (f1 date NOT NULL, f2 bigint, f3 bigint) PARTITION BY RANGE (f1);
 CREATE TABLE gtest_child PARTITION OF gtest_parent (
-    f3 WITH OPTIONS GENERATED ALWAYS AS (f2 * 2) STORED
+    f3 WITH OPTIONS GENERATED ALWAYS AS (f2 * 2) VIRTUAL
 ) FOR VALUES FROM ('2016-07-01') TO ('2016-08-01'); -- error
 ERROR:  child column "f3" specifies generation expression
 HINT:  A child table column cannot be generated unless its parent column is.
-CREATE TABLE gtest_child (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) STORED);
+CREATE TABLE gtest_child (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) VIRTUAL);
 ALTER TABLE gtest_parent ATTACH PARTITION gtest_child FOR VALUES FROM ('2016-07-01') TO ('2016-08-01'); -- error
 ERROR:  column "f3" in child table must not be a generated column
 DROP TABLE gtest_parent, gtest_child;
-CREATE TABLE gtest_parent (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE (f1);
+CREATE TABLE gtest_parent (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) VIRTUAL) PARTITION BY RANGE (f1);
 CREATE TABLE gtest_child PARTITION OF gtest_parent
   FOR VALUES FROM ('2016-07-01') TO ('2016-08-01');  -- inherits gen expr
 CREATE TABLE gtest_child2 PARTITION OF gtest_parent (
-    f3 WITH OPTIONS GENERATED ALWAYS AS (f2 * 22) STORED  -- overrides gen expr
+    f3 WITH OPTIONS GENERATED ALWAYS AS (f2 * 22) VIRTUAL  -- overrides gen expr
 ) FOR VALUES FROM ('2016-08-01') TO ('2016-09-01');
 CREATE TABLE gtest_child3 PARTITION OF gtest_parent (
     f3 DEFAULT 42  -- error
@@ -807,33 +710,33 @@ ALTER TABLE gtest_parent ATTACH PARTITION gtest_child3 FOR VALUES FROM ('2016-09
 ERROR:  table "gtest_child3" being attached contains an identity column "f3"
 DETAIL:  The new partition may not contain an identity column.
 DROP TABLE gtest_child3;
-CREATE TABLE gtest_child3 (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 33) STORED);
+CREATE TABLE gtest_child3 (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 33) VIRTUAL);
 ALTER TABLE gtest_parent ATTACH PARTITION gtest_child3 FOR VALUES FROM ('2016-09-01') TO ('2016-10-01');
 \d gtest_child
-                  Table "generated_stored_tests.gtest_child"
- Column |  Type  | Collation | Nullable |               Default               
---------+--------+-----------+----------+-------------------------------------
+              Table "generated_virtual_tests.gtest_child"
+ Column |  Type  | Collation | Nullable |           Default            
+--------+--------+-----------+----------+------------------------------
  f1     | date   |           | not null | 
  f2     | bigint |           |          | 
- f3     | bigint |           |          | generated always as (f2 * 2) stored
+ f3     | bigint |           |          | generated always as (f2 * 2)
 Partition of: gtest_parent FOR VALUES FROM ('07-01-2016') TO ('08-01-2016')
 
 \d gtest_child2
-                  Table "generated_stored_tests.gtest_child2"
- Column |  Type  | Collation | Nullable |               Default                
---------+--------+-----------+----------+--------------------------------------
+              Table "generated_virtual_tests.gtest_child2"
+ Column |  Type  | Collation | Nullable |            Default            
+--------+--------+-----------+----------+-------------------------------
  f1     | date   |           | not null | 
  f2     | bigint |           |          | 
- f3     | bigint |           |          | generated always as (f2 * 22) stored
+ f3     | bigint |           |          | generated always as (f2 * 22)
 Partition of: gtest_parent FOR VALUES FROM ('08-01-2016') TO ('09-01-2016')
 
 \d gtest_child3
-                  Table "generated_stored_tests.gtest_child3"
- Column |  Type  | Collation | Nullable |               Default                
---------+--------+-----------+----------+--------------------------------------
+              Table "generated_virtual_tests.gtest_child3"
+ Column |  Type  | Collation | Nullable |            Default            
+--------+--------+-----------+----------+-------------------------------
  f1     | date   |           | not null | 
  f2     | bigint |           |          | 
- f3     | bigint |           |          | generated always as (f2 * 33) stored
+ f3     | bigint |           |          | generated always as (f2 * 33)
 Partition of: gtest_parent FOR VALUES FROM ('09-01-2016') TO ('10-01-2016')
 
 INSERT INTO gtest_parent (f1, f2) VALUES ('2016-07-15', 1);
@@ -844,7 +747,7 @@ SELECT tableoid::regclass, * FROM gtest_parent ORDER BY 1, 2, 3;
 --------------+------------+----+----
  gtest_child  | 07-15-2016 |  1 |  2
  gtest_child  | 07-15-2016 |  2 |  4
- gtest_child2 | 08-15-2016 |  3 | 66
+ gtest_child2 | 08-15-2016 |  3 |  6
 (3 rows)
 
 UPDATE gtest_parent SET f1 = f1 + 60 WHERE f2 = 1;
@@ -852,95 +755,98 @@ SELECT tableoid::regclass, * FROM gtest_parent ORDER BY 1, 2, 3;
    tableoid   |     f1     | f2 | f3 
 --------------+------------+----+----
  gtest_child  | 07-15-2016 |  2 |  4
- gtest_child2 | 08-15-2016 |  3 | 66
- gtest_child3 | 09-13-2016 |  1 | 33
+ gtest_child2 | 08-15-2016 |  3 |  6
+ gtest_child3 | 09-13-2016 |  1 |  2
 (3 rows)
 
 -- alter only parent's and one child's generation expression
 ALTER TABLE ONLY gtest_parent ALTER COLUMN f3 SET EXPRESSION AS (f2 * 4);
+ERROR:  column "f3" of relation "gtest_parent" is not a generated column
 ALTER TABLE gtest_child ALTER COLUMN f3 SET EXPRESSION AS (f2 * 10);
+ERROR:  column "f3" of relation "gtest_child" is not a generated column
 \d gtest_parent
-           Partitioned table "generated_stored_tests.gtest_parent"
- Column |  Type  | Collation | Nullable |               Default               
---------+--------+-----------+----------+-------------------------------------
+       Partitioned table "generated_virtual_tests.gtest_parent"
+ Column |  Type  | Collation | Nullable |           Default            
+--------+--------+-----------+----------+------------------------------
  f1     | date   |           | not null | 
  f2     | bigint |           |          | 
- f3     | bigint |           |          | generated always as (f2 * 4) stored
+ f3     | bigint |           |          | generated always as (f2 * 2)
 Partition key: RANGE (f1)
 Number of partitions: 3 (Use \d+ to list them.)
 
 \d gtest_child
-                  Table "generated_stored_tests.gtest_child"
- Column |  Type  | Collation | Nullable |               Default                
---------+--------+-----------+----------+--------------------------------------
+              Table "generated_virtual_tests.gtest_child"
+ Column |  Type  | Collation | Nullable |           Default            
+--------+--------+-----------+----------+------------------------------
  f1     | date   |           | not null | 
  f2     | bigint |           |          | 
- f3     | bigint |           |          | generated always as (f2 * 10) stored
+ f3     | bigint |           |          | generated always as (f2 * 2)
 Partition of: gtest_parent FOR VALUES FROM ('07-01-2016') TO ('08-01-2016')
 
 \d gtest_child2
-                  Table "generated_stored_tests.gtest_child2"
- Column |  Type  | Collation | Nullable |               Default                
---------+--------+-----------+----------+--------------------------------------
+              Table "generated_virtual_tests.gtest_child2"
+ Column |  Type  | Collation | Nullable |            Default            
+--------+--------+-----------+----------+-------------------------------
  f1     | date   |           | not null | 
  f2     | bigint |           |          | 
- f3     | bigint |           |          | generated always as (f2 * 22) stored
+ f3     | bigint |           |          | generated always as (f2 * 22)
 Partition of: gtest_parent FOR VALUES FROM ('08-01-2016') TO ('09-01-2016')
 
 \d gtest_child3
-                  Table "generated_stored_tests.gtest_child3"
- Column |  Type  | Collation | Nullable |               Default                
---------+--------+-----------+----------+--------------------------------------
+              Table "generated_virtual_tests.gtest_child3"
+ Column |  Type  | Collation | Nullable |            Default            
+--------+--------+-----------+----------+-------------------------------
  f1     | date   |           | not null | 
  f2     | bigint |           |          | 
- f3     | bigint |           |          | generated always as (f2 * 33) stored
+ f3     | bigint |           |          | generated always as (f2 * 33)
 Partition of: gtest_parent FOR VALUES FROM ('09-01-2016') TO ('10-01-2016')
 
 SELECT tableoid::regclass, * FROM gtest_parent ORDER BY 1, 2, 3;
    tableoid   |     f1     | f2 | f3 
 --------------+------------+----+----
- gtest_child  | 07-15-2016 |  2 | 20
- gtest_child2 | 08-15-2016 |  3 | 66
- gtest_child3 | 09-13-2016 |  1 | 33
+ gtest_child  | 07-15-2016 |  2 |  4
+ gtest_child2 | 08-15-2016 |  3 |  6
+ gtest_child3 | 09-13-2016 |  1 |  2
 (3 rows)
 
 -- alter generation expression of parent and all its children altogether
 ALTER TABLE gtest_parent ALTER COLUMN f3 SET EXPRESSION AS (f2 * 2);
+ERROR:  column "f3" of relation "gtest_parent" is not a generated column
 \d gtest_parent
-           Partitioned table "generated_stored_tests.gtest_parent"
- Column |  Type  | Collation | Nullable |               Default               
---------+--------+-----------+----------+-------------------------------------
+       Partitioned table "generated_virtual_tests.gtest_parent"
+ Column |  Type  | Collation | Nullable |           Default            
+--------+--------+-----------+----------+------------------------------
  f1     | date   |           | not null | 
  f2     | bigint |           |          | 
- f3     | bigint |           |          | generated always as (f2 * 2) stored
+ f3     | bigint |           |          | generated always as (f2 * 2)
 Partition key: RANGE (f1)
 Number of partitions: 3 (Use \d+ to list them.)
 
 \d gtest_child
-                  Table "generated_stored_tests.gtest_child"
- Column |  Type  | Collation | Nullable |               Default               
---------+--------+-----------+----------+-------------------------------------
+              Table "generated_virtual_tests.gtest_child"
+ Column |  Type  | Collation | Nullable |           Default            
+--------+--------+-----------+----------+------------------------------
  f1     | date   |           | not null | 
  f2     | bigint |           |          | 
- f3     | bigint |           |          | generated always as (f2 * 2) stored
+ f3     | bigint |           |          | generated always as (f2 * 2)
 Partition of: gtest_parent FOR VALUES FROM ('07-01-2016') TO ('08-01-2016')
 
 \d gtest_child2
-                 Table "generated_stored_tests.gtest_child2"
- Column |  Type  | Collation | Nullable |               Default               
---------+--------+-----------+----------+-------------------------------------
+              Table "generated_virtual_tests.gtest_child2"
+ Column |  Type  | Collation | Nullable |            Default            
+--------+--------+-----------+----------+-------------------------------
  f1     | date   |           | not null | 
  f2     | bigint |           |          | 
- f3     | bigint |           |          | generated always as (f2 * 2) stored
+ f3     | bigint |           |          | generated always as (f2 * 22)
 Partition of: gtest_parent FOR VALUES FROM ('08-01-2016') TO ('09-01-2016')
 
 \d gtest_child3
-                 Table "generated_stored_tests.gtest_child3"
- Column |  Type  | Collation | Nullable |               Default               
---------+--------+-----------+----------+-------------------------------------
+              Table "generated_virtual_tests.gtest_child3"
+ Column |  Type  | Collation | Nullable |            Default            
+--------+--------+-----------+----------+-------------------------------
  f1     | date   |           | not null | 
  f2     | bigint |           |          | 
- f3     | bigint |           |          | generated always as (f2 * 2) stored
+ f3     | bigint |           |          | generated always as (f2 * 33)
 Partition of: gtest_parent FOR VALUES FROM ('09-01-2016') TO ('10-01-2016')
 
 SELECT tableoid::regclass, * FROM gtest_parent ORDER BY 1, 2, 3;
@@ -953,54 +859,53 @@ SELECT tableoid::regclass, * FROM gtest_parent ORDER BY 1, 2, 3;
 
 -- we leave these tables around for purposes of testing dump/reload/upgrade
 -- generated columns in partition key (not allowed)
-CREATE TABLE gtest_part_key (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE (f3);
+CREATE TABLE gtest_part_key (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) VIRTUAL) PARTITION BY RANGE (f3);
 ERROR:  cannot use generated column in partition key
-LINE 1: ...ENERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE (f3);
+LINE 1: ...NERATED ALWAYS AS (f2 * 2) VIRTUAL) PARTITION BY RANGE (f3);
                                                                    ^
 DETAIL:  Column "f3" is a generated column.
-CREATE TABLE gtest_part_key (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE ((f3 * 3));
+CREATE TABLE gtest_part_key (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) VIRTUAL) PARTITION BY RANGE ((f3 * 3));
 ERROR:  cannot use generated column in partition key
-LINE 1: ...ED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE ((f3 * 3));
+LINE 1: ...D ALWAYS AS (f2 * 2) VIRTUAL) PARTITION BY RANGE ((f3 * 3));
                                                              ^
 DETAIL:  Column "f3" is a generated column.
 -- ALTER TABLE ... ADD COLUMN
 CREATE TABLE gtest25 (a int PRIMARY KEY);
 INSERT INTO gtest25 VALUES (3), (4);
-ALTER TABLE gtest25 ADD COLUMN b int GENERATED ALWAYS AS (a * 2) STORED, ALTER COLUMN b SET EXPRESSION AS (a * 3);
+ALTER TABLE gtest25 ADD COLUMN b int GENERATED ALWAYS AS (a * 2) VIRTUAL, ALTER COLUMN b SET EXPRESSION AS (a * 3);
+ERROR:  column "b" of relation "gtest25" is not a generated column
 SELECT * FROM gtest25 ORDER BY a;
- a | b  
----+----
- 3 |  9
- 4 | 12
+ a 
+---
+ 3
+ 4
 (2 rows)
 
-ALTER TABLE gtest25 ADD COLUMN x int GENERATED ALWAYS AS (b * 4) STORED;  -- error
-ERROR:  cannot use generated column "b" in column generation expression
-DETAIL:  A generated column cannot reference another generated column.
-ALTER TABLE gtest25 ADD COLUMN x int GENERATED ALWAYS AS (z * 4) STORED;  -- error
+ALTER TABLE gtest25 ADD COLUMN x int GENERATED ALWAYS AS (b * 4) VIRTUAL;  -- error
+ERROR:  column "b" does not exist
+ALTER TABLE gtest25 ADD COLUMN x int GENERATED ALWAYS AS (z * 4) VIRTUAL;  -- error
 ERROR:  column "z" does not exist
 ALTER TABLE gtest25 ADD COLUMN c int DEFAULT 42,
-  ADD COLUMN x int GENERATED ALWAYS AS (c * 4) STORED;
+  ADD COLUMN x int GENERATED ALWAYS AS (c * 4) VIRTUAL;
 ALTER TABLE gtest25 ADD COLUMN d int DEFAULT 101;
 ALTER TABLE gtest25 ALTER COLUMN d SET DATA TYPE float8,
-  ADD COLUMN y float8 GENERATED ALWAYS AS (d * 4) STORED;
+  ADD COLUMN y float8 GENERATED ALWAYS AS (d * 4) VIRTUAL;
 SELECT * FROM gtest25 ORDER BY a;
- a | b  | c  |  x  |  d  |  y  
----+----+----+-----+-----+-----
- 3 |  9 | 42 | 168 | 101 | 404
- 4 | 12 | 42 | 168 | 101 | 404
+ a | c  |  x  |  d  |  y  
+---+----+-----+-----+-----
+ 3 | 42 | 168 | 101 | 404
+ 4 | 42 | 168 | 101 | 404
 (2 rows)
 
 \d gtest25
-                                 Table "generated_stored_tests.gtest25"
- Column |       Type       | Collation | Nullable |                       Default                        
---------+------------------+-----------+----------+------------------------------------------------------
+                             Table "generated_virtual_tests.gtest25"
+ Column |       Type       | Collation | Nullable |                    Default                    
+--------+------------------+-----------+----------+-----------------------------------------------
  a      | integer          |           | not null | 
- b      | integer          |           |          | generated always as (a * 3) stored
  c      | integer          |           |          | 42
- x      | integer          |           |          | generated always as (c * 4) stored
+ x      | integer          |           |          | generated always as (c * 4)
  d      | double precision |           |          | 101
- y      | double precision |           |          | generated always as (d * 4::double precision) stored
+ y      | double precision |           |          | generated always as (d * 4::double precision)
 Indexes:
     "gtest25_pkey" PRIMARY KEY, btree (a)
 
@@ -1008,7 +913,7 @@ Indexes:
 CREATE TABLE gtest27 (
     a int,
     b int,
-    x int GENERATED ALWAYS AS ((a + b) * 2) STORED
+    x int GENERATED ALWAYS AS ((a + b) * 2) VIRTUAL
 );
 INSERT INTO gtest27 (a, b) VALUES (3, 7), (4, 11);
 ALTER TABLE gtest27 ALTER COLUMN a TYPE text;  -- error
@@ -1016,12 +921,12 @@ ERROR:  cannot alter type of a column used by a generated column
 DETAIL:  Column "a" is used by generated column "x".
 ALTER TABLE gtest27 ALTER COLUMN x TYPE numeric;
 \d gtest27
-                        Table "generated_stored_tests.gtest27"
- Column |  Type   | Collation | Nullable |                  Default                   
---------+---------+-----------+----------+--------------------------------------------
+                    Table "generated_virtual_tests.gtest27"
+ Column |  Type   | Collation | Nullable |               Default               
+--------+---------+-----------+----------+-------------------------------------
  a      | integer |           |          | 
  b      | integer |           |          | 
- x      | numeric |           |          | generated always as (((a + b) * 2)) stored
+ x      | numeric |           |          | generated always as (((a + b) * 2))
 
 SELECT * FROM gtest27;
  a | b  | x  
@@ -1034,20 +939,19 @@ ALTER TABLE gtest27 ALTER COLUMN x TYPE boolean USING x <> 0;  -- error
 ERROR:  generation expression for column "x" cannot be cast automatically to type boolean
 ALTER TABLE gtest27 ALTER COLUMN x DROP DEFAULT;  -- error
 ERROR:  column "x" of relation "gtest27" is a generated column
-HINT:  Use ALTER TABLE ... ALTER COLUMN ... DROP EXPRESSION instead.
 -- It's possible to alter the column types this way:
 ALTER TABLE gtest27
   DROP COLUMN x,
   ALTER COLUMN a TYPE bigint,
   ALTER COLUMN b TYPE bigint,
-  ADD COLUMN x bigint GENERATED ALWAYS AS ((a + b) * 2) STORED;
+  ADD COLUMN x bigint GENERATED ALWAYS AS ((a + b) * 2) VIRTUAL;
 \d gtest27
-                      Table "generated_stored_tests.gtest27"
- Column |  Type  | Collation | Nullable |                 Default                  
---------+--------+-----------+----------+------------------------------------------
+                  Table "generated_virtual_tests.gtest27"
+ Column |  Type  | Collation | Nullable |              Default              
+--------+--------+-----------+----------+-----------------------------------
  a      | bigint |           |          | 
  b      | bigint |           |          | 
- x      | bigint |           |          | generated always as ((a + b) * 2) stored
+ x      | bigint |           |          | generated always as ((a + b) * 2)
 
 -- Ideally you could just do this, but not today (and should x change type?):
 ALTER TABLE gtest27
@@ -1056,12 +960,12 @@ ALTER TABLE gtest27
 ERROR:  cannot alter type of a column used by a generated column
 DETAIL:  Column "a" is used by generated column "x".
 \d gtest27
-                      Table "generated_stored_tests.gtest27"
- Column |  Type  | Collation | Nullable |                 Default                  
---------+--------+-----------+----------+------------------------------------------
+                  Table "generated_virtual_tests.gtest27"
+ Column |  Type  | Collation | Nullable |              Default              
+--------+--------+-----------+----------+-----------------------------------
  a      | bigint |           |          | 
  b      | bigint |           |          | 
- x      | bigint |           |          | generated always as ((a + b) * 2) stored
+ x      | bigint |           |          | generated always as ((a + b) * 2)
 
 SELECT * FROM gtest27;
  a | b  | x  
@@ -1073,7 +977,7 @@ SELECT * FROM gtest27;
 -- ALTER TABLE ... ALTER COLUMN ... DROP EXPRESSION
 CREATE TABLE gtest29 (
     a int,
-    b int GENERATED ALWAYS AS (a * 2) STORED
+    b int GENERATED ALWAYS AS (a * 2) VIRTUAL
 );
 INSERT INTO gtest29 (a) VALUES (3), (4);
 SELECT * FROM gtest29;
@@ -1084,11 +988,11 @@ SELECT * FROM gtest29;
 (2 rows)
 
 \d gtest29
-                    Table "generated_stored_tests.gtest29"
- Column |  Type   | Collation | Nullable |              Default               
---------+---------+-----------+----------+------------------------------------
+                Table "generated_virtual_tests.gtest29"
+ Column |  Type   | Collation | Nullable |           Default           
+--------+---------+-----------+----------+-----------------------------
  a      | integer |           |          | 
- b      | integer |           |          | generated always as (a * 2) stored
+ b      | integer |           |          | generated always as (a * 2)
 
 ALTER TABLE gtest29 ALTER COLUMN a SET EXPRESSION AS (a * 3);  -- error
 ERROR:  column "a" of relation "gtest29" is not a generated column
@@ -1098,93 +1002,101 @@ ALTER TABLE gtest29 ALTER COLUMN a DROP EXPRESSION IF EXISTS;  -- notice
 NOTICE:  column "a" of relation "gtest29" is not a stored generated column, skipping
 -- Change the expression
 ALTER TABLE gtest29 ALTER COLUMN b SET EXPRESSION AS (a * 3);
+ERROR:  column "b" of relation "gtest29" is not a generated column
 SELECT * FROM gtest29;
- a | b  
----+----
- 3 |  9
- 4 | 12
+ a | b 
+---+---
+ 3 | 6
+ 4 | 8
 (2 rows)
 
 \d gtest29
-                    Table "generated_stored_tests.gtest29"
- Column |  Type   | Collation | Nullable |              Default               
---------+---------+-----------+----------+------------------------------------
+                Table "generated_virtual_tests.gtest29"
+ Column |  Type   | Collation | Nullable |           Default           
+--------+---------+-----------+----------+-----------------------------
  a      | integer |           |          | 
- b      | integer |           |          | generated always as (a * 3) stored
+ b      | integer |           |          | generated always as (a * 2)
 
 ALTER TABLE gtest29 ALTER COLUMN b DROP EXPRESSION;
+ERROR:  column "b" of relation "gtest29" is not a stored generated column
 INSERT INTO gtest29 (a) VALUES (5);
 INSERT INTO gtest29 (a, b) VALUES (6, 66);
+ERROR:  cannot insert a non-DEFAULT value into column "b"
+DETAIL:  Column "b" is a generated column.
 SELECT * FROM gtest29;
  a | b  
 ---+----
- 3 |  9
- 4 | 12
- 5 |   
- 6 | 66
-(4 rows)
+ 3 |  6
+ 4 |  8
+ 5 | 10
+(3 rows)
 
 \d gtest29
-      Table "generated_stored_tests.gtest29"
- Column |  Type   | Collation | Nullable | Default 
---------+---------+-----------+----------+---------
+                Table "generated_virtual_tests.gtest29"
+ Column |  Type   | Collation | Nullable |           Default           
+--------+---------+-----------+----------+-----------------------------
  a      | integer |           |          | 
- b      | integer |           |          | 
+ b      | integer |           |          | generated always as (a * 2)
 
 -- check that dependencies between columns have also been removed
 ALTER TABLE gtest29 DROP COLUMN a;  -- should not drop b
+ERROR:  cannot drop column a of table gtest29 because other objects depend on it
+DETAIL:  column b of table gtest29 depends on column a of table gtest29
+HINT:  Use DROP ... CASCADE to drop the dependent objects too.
 \d gtest29
-      Table "generated_stored_tests.gtest29"
- Column |  Type   | Collation | Nullable | Default 
---------+---------+-----------+----------+---------
- b      | integer |           |          | 
+                Table "generated_virtual_tests.gtest29"
+ Column |  Type   | Collation | Nullable |           Default           
+--------+---------+-----------+----------+-----------------------------
+ a      | integer |           |          | 
+ b      | integer |           |          | generated always as (a * 2)
 
 -- with inheritance
 CREATE TABLE gtest30 (
     a int,
-    b int GENERATED ALWAYS AS (a * 2) STORED
+    b int GENERATED ALWAYS AS (a * 2) VIRTUAL
 );
 CREATE TABLE gtest30_1 () INHERITS (gtest30);
 ALTER TABLE gtest30 ALTER COLUMN b DROP EXPRESSION;
+ERROR:  column "b" of relation "gtest30" is not a stored generated column
 \d gtest30
-      Table "generated_stored_tests.gtest30"
- Column |  Type   | Collation | Nullable | Default 
---------+---------+-----------+----------+---------
+                Table "generated_virtual_tests.gtest30"
+ Column |  Type   | Collation | Nullable |           Default           
+--------+---------+-----------+----------+-----------------------------
  a      | integer |           |          | 
- b      | integer |           |          | 
+ b      | integer |           |          | generated always as (a * 2)
 Number of child tables: 1 (Use \d+ to list them.)
 
 \d gtest30_1
-     Table "generated_stored_tests.gtest30_1"
- Column |  Type   | Collation | Nullable | Default 
---------+---------+-----------+----------+---------
+               Table "generated_virtual_tests.gtest30_1"
+ Column |  Type   | Collation | Nullable |           Default           
+--------+---------+-----------+----------+-----------------------------
  a      | integer |           |          | 
- b      | integer |           |          | 
+ b      | integer |           |          | generated always as (a * 2)
 Inherits: gtest30
 
 DROP TABLE gtest30 CASCADE;
 NOTICE:  drop cascades to table gtest30_1
 CREATE TABLE gtest30 (
     a int,
-    b int GENERATED ALWAYS AS (a * 2) STORED
+    b int GENERATED ALWAYS AS (a * 2) VIRTUAL
 );
 CREATE TABLE gtest30_1 () INHERITS (gtest30);
 ALTER TABLE ONLY gtest30 ALTER COLUMN b DROP EXPRESSION;  -- error
 ERROR:  ALTER TABLE / DROP EXPRESSION must be applied to child tables too
 \d gtest30
-                    Table "generated_stored_tests.gtest30"
- Column |  Type   | Collation | Nullable |              Default               
---------+---------+-----------+----------+------------------------------------
+                Table "generated_virtual_tests.gtest30"
+ Column |  Type   | Collation | Nullable |           Default           
+--------+---------+-----------+----------+-----------------------------
  a      | integer |           |          | 
- b      | integer |           |          | generated always as (a * 2) stored
+ b      | integer |           |          | generated always as (a * 2)
 Number of child tables: 1 (Use \d+ to list them.)
 
 \d gtest30_1
-                   Table "generated_stored_tests.gtest30_1"
- Column |  Type   | Collation | Nullable |              Default               
---------+---------+-----------+----------+------------------------------------
+               Table "generated_virtual_tests.gtest30_1"
+ Column |  Type   | Collation | Nullable |           Default           
+--------+---------+-----------+----------+-----------------------------
  a      | integer |           |          | 
- b      | integer |           |          | generated always as (a * 2) stored
+ b      | integer |           |          | generated always as (a * 2)
 Inherits: gtest30
 
 ALTER TABLE gtest30_1 ALTER COLUMN b DROP EXPRESSION;  -- error
@@ -1192,7 +1104,7 @@ ERROR:  cannot drop generation expression from inherited column
 -- triggers
 CREATE TABLE gtest26 (
     a int PRIMARY KEY,
-    b int GENERATED ALWAYS AS (a * 2) STORED
+    b int GENERATED ALWAYS AS (a * 2) VIRTUAL
 );
 CREATE FUNCTION gtest_trigger_func() RETURNS trigger
   LANGUAGE plpgsql
@@ -1245,7 +1157,7 @@ CREATE TRIGGER gtest4 AFTER INSERT OR UPDATE ON gtest26
   EXECUTE PROCEDURE gtest_trigger_func();
 INSERT INTO gtest26 (a) VALUES (-2), (0), (3);
 INFO:  gtest2: BEFORE: new = (-2,)
-INFO:  gtest4: AFTER: new = (-2,-4)
+INFO:  gtest4: AFTER: new = (-2,)
 SELECT * FROM gtest26 ORDER BY a;
  a  | b  
 ----+----
@@ -1255,12 +1167,12 @@ SELECT * FROM gtest26 ORDER BY a;
 (3 rows)
 
 UPDATE gtest26 SET a = a * -2;
-INFO:  gtest1: BEFORE: old = (-2,-4)
+INFO:  gtest1: BEFORE: old = (-2,)
 INFO:  gtest1: BEFORE: new = (4,)
-INFO:  gtest3: AFTER: old = (-2,-4)
-INFO:  gtest3: AFTER: new = (4,8)
-INFO:  gtest4: AFTER: old = (3,6)
-INFO:  gtest4: AFTER: new = (-6,-12)
+INFO:  gtest3: AFTER: old = (-2,)
+INFO:  gtest3: AFTER: new = (4,)
+INFO:  gtest4: AFTER: old = (3,)
+INFO:  gtest4: AFTER: new = (-6,)
 SELECT * FROM gtest26 ORDER BY a;
  a  |  b  
 ----+-----
@@ -1270,8 +1182,8 @@ SELECT * FROM gtest26 ORDER BY a;
 (3 rows)
 
 DELETE FROM gtest26 WHERE a = -6;
-INFO:  gtest1: BEFORE: old = (-6,-12)
-INFO:  gtest3: AFTER: old = (-6,-12)
+INFO:  gtest1: BEFORE: old = (-6,)
+INFO:  gtest3: AFTER: old = (-6,)
 SELECT * FROM gtest26 ORDER BY a;
  a | b 
 ---+---
@@ -1282,6 +1194,8 @@ SELECT * FROM gtest26 ORDER BY a;
 DROP TRIGGER gtest1 ON gtest26;
 DROP TRIGGER gtest2 ON gtest26;
 DROP TRIGGER gtest3 ON gtest26;
+-- check disallowed modification of virtual columns
+-- TODO
 -- Check that an UPDATE of "a" fires the trigger for UPDATE OF b, per
 -- SQL standard.
 CREATE FUNCTION gtest_trigger_func3() RETURNS trigger
@@ -1295,9 +1209,11 @@ $$;
 CREATE TRIGGER gtest11 BEFORE UPDATE OF b ON gtest26
   FOR EACH ROW
   EXECUTE PROCEDURE gtest_trigger_func3();
+ERROR:  virtual generated columns are not supported as trigger columns
+DETAIL:  Column "b" is a virtual generated column.
 UPDATE gtest26 SET a = 1 WHERE a = 0;
-NOTICE:  OK
 DROP TRIGGER gtest11 ON gtest26;
+ERROR:  trigger "gtest11" for table "gtest26" does not exist
 TRUNCATE gtest26;
 -- check that modifications of stored generated columns in triggers do
 -- not get propagated
@@ -1321,14 +1237,13 @@ CREATE TRIGGER gtest12_03 BEFORE UPDATE ON gtest26
   EXECUTE PROCEDURE gtest_trigger_func();
 INSERT INTO gtest26 (a) VALUES (1);
 UPDATE gtest26 SET a = 11 WHERE a = 1;
-INFO:  gtest12_01: BEFORE: old = (1,2)
+INFO:  gtest12_01: BEFORE: old = (1,)
 INFO:  gtest12_01: BEFORE: new = (11,)
-INFO:  gtest12_03: BEFORE: old = (1,2)
-INFO:  gtest12_03: BEFORE: new = (10,)
+ERROR:  trigger modified virtual generated column value
 SELECT * FROM gtest26 ORDER BY a;
- a  | b  
-----+----
- 10 | 20
+ a | b 
+---+---
+ 1 | 2
 (1 row)
 
 -- LIKE INCLUDING GENERATED and dropped column handling
@@ -1336,22 +1251,22 @@ CREATE TABLE gtest28a (
   a int,
   b int,
   c int,
-  x int GENERATED ALWAYS AS (b * 2) STORED
+  x int GENERATED ALWAYS AS (b * 2) VIRTUAL
 );
 ALTER TABLE gtest28a DROP COLUMN a;
 CREATE TABLE gtest28b (LIKE gtest28a INCLUDING GENERATED);
 \d gtest28*
-                   Table "generated_stored_tests.gtest28a"
- Column |  Type   | Collation | Nullable |              Default               
---------+---------+-----------+----------+------------------------------------
+               Table "generated_virtual_tests.gtest28a"
+ Column |  Type   | Collation | Nullable |           Default           
+--------+---------+-----------+----------+-----------------------------
  b      | integer |           |          | 
  c      | integer |           |          | 
- x      | integer |           |          | generated always as (b * 2) stored
+ x      | integer |           |          | generated always as (b * 2)
 
-                   Table "generated_stored_tests.gtest28b"
- Column |  Type   | Collation | Nullable |              Default               
---------+---------+-----------+----------+------------------------------------
+               Table "generated_virtual_tests.gtest28b"
+ Column |  Type   | Collation | Nullable |           Default           
+--------+---------+-----------+----------+-----------------------------
  b      | integer |           |          | 
  c      | integer |           |          | 
- x      | integer |           |          | generated always as (b * 2) stored
+ x      | integer |           |          | generated always as (b * 2)
 
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index f345d6b45aa..29415191578 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -68,6 +68,9 @@ test: select_into select_distinct select_distinct_on select_implicit select_havi
 # ----------
 test: brin gin gist spgist privileges init_privs security_label collate matview lock replica_identity rowsecurity object_address tablesample groupingsets drop_operator password identity generated_stored join_hash
 
+# TODO: find a place for this (above group is full)
+test: generated_virtual
+
 # ----------
 # Additional BRIN tests
 # ----------
diff --git a/src/test/regress/sql/create_table_like.sql b/src/test/regress/sql/create_table_like.sql
index 4929d373a2f..3ae42a99272 100644
--- a/src/test/regress/sql/create_table_like.sql
+++ b/src/test/regress/sql/create_table_like.sql
@@ -51,7 +51,7 @@ CREATE TABLE test_like_id_3 (LIKE test_like_id_1 INCLUDING IDENTITY);
 SELECT * FROM test_like_id_3;  -- identity was copied and applied
 DROP TABLE test_like_id_1, test_like_id_2, test_like_id_3;
 
-CREATE TABLE test_like_gen_1 (a int, b int GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE test_like_gen_1 (a int, b int GENERATED ALWAYS AS (a * 2) STORED, c int GENERATED ALWAYS AS (a * 3) VIRTUAL);
 \d test_like_gen_1
 INSERT INTO test_like_gen_1 (a) VALUES (1);
 SELECT * FROM test_like_gen_1;
diff --git a/src/test/regress/sql/generated_stored.sql b/src/test/regress/sql/generated_stored.sql
index c18e0e1f655..03ea1954903 100644
--- a/src/test/regress/sql/generated_stored.sql
+++ b/src/test/regress/sql/generated_stored.sql
@@ -1,5 +1,5 @@
 -- sanity check of system catalog
-SELECT attrelid, attname, attgenerated FROM pg_attribute WHERE attgenerated NOT IN ('', 's');
+SELECT attrelid, attname, attgenerated FROM pg_attribute WHERE attgenerated NOT IN ('', 's', 'v');
 
 
 CREATE SCHEMA generated_stored_tests;
diff --git a/src/test/regress/sql/generated_stored.sql b/src/test/regress/sql/generated_virtual.sql
similarity index 76%
copy from src/test/regress/sql/generated_stored.sql
copy to src/test/regress/sql/generated_virtual.sql
index c18e0e1f655..64a0109fd25 100644
--- a/src/test/regress/sql/generated_stored.sql
+++ b/src/test/regress/sql/generated_virtual.sql
@@ -1,55 +1,55 @@
 -- sanity check of system catalog
-SELECT attrelid, attname, attgenerated FROM pg_attribute WHERE attgenerated NOT IN ('', 's');
+SELECT attrelid, attname, attgenerated FROM pg_attribute WHERE attgenerated NOT IN ('', 's', 'v');
 
 
-CREATE SCHEMA generated_stored_tests;
-GRANT USAGE ON SCHEMA generated_stored_tests TO PUBLIC;
-SET search_path = generated_stored_tests;
+CREATE SCHEMA generated_virtual_tests;
+GRANT USAGE ON SCHEMA generated_virtual_tests TO PUBLIC;
+SET search_path = generated_virtual_tests;
 
-CREATE TABLE gtest0 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (55) STORED);
-CREATE TABLE gtest1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE gtest0 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (55) VIRTUAL);
+CREATE TABLE gtest1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL);
 
-SELECT table_name, column_name, column_default, is_nullable, is_generated, generation_expression FROM information_schema.columns WHERE table_schema = 'generated_stored_tests' ORDER BY 1, 2;
+SELECT table_name, column_name, column_default, is_nullable, is_generated, generation_expression FROM information_schema.columns WHERE table_schema = 'generated_virtual_tests' ORDER BY 1, 2;
 
-SELECT table_name, column_name, dependent_column FROM information_schema.column_column_usage WHERE table_schema = 'generated_stored_tests' ORDER BY 1, 2, 3;
+SELECT table_name, column_name, dependent_column FROM information_schema.column_column_usage WHERE table_schema = 'generated_virtual_tests' ORDER BY 1, 2, 3;
 
 \d gtest1
 
 -- duplicate generated
-CREATE TABLE gtest_err_1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED GENERATED ALWAYS AS (a * 3) STORED);
+CREATE TABLE gtest_err_1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL GENERATED ALWAYS AS (a * 3) VIRTUAL);
 
 -- references to other generated columns, including self-references
-CREATE TABLE gtest_err_2a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (b * 2) STORED);
-CREATE TABLE gtest_err_2b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED, c int GENERATED ALWAYS AS (b * 3) STORED);
+CREATE TABLE gtest_err_2a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (b * 2) VIRTUAL);
+CREATE TABLE gtest_err_2b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL, c int GENERATED ALWAYS AS (b * 3) VIRTUAL);
 -- a whole-row var is a self-reference on steroids, so disallow that too
 CREATE TABLE gtest_err_2c (a int PRIMARY KEY,
-    b int GENERATED ALWAYS AS (num_nulls(gtest_err_2c)) STORED);
+    b int GENERATED ALWAYS AS (num_nulls(gtest_err_2c)) VIRTUAL);
 
 -- invalid reference
-CREATE TABLE gtest_err_3 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (c * 2) STORED);
+CREATE TABLE gtest_err_3 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (c * 2) VIRTUAL);
 
 -- generation expression must be immutable
-CREATE TABLE gtest_err_4 (a int PRIMARY KEY, b double precision GENERATED ALWAYS AS (random()) STORED);
+CREATE TABLE gtest_err_4 (a int PRIMARY KEY, b double precision GENERATED ALWAYS AS (random()) VIRTUAL);
 -- ... but be sure that the immutability test is accurate
-CREATE TABLE gtest2 (a int, b text GENERATED ALWAYS AS (a || ' sec') STORED);
+CREATE TABLE gtest2 (a int, b text GENERATED ALWAYS AS (a || ' sec') VIRTUAL);
 DROP TABLE gtest2;
 
 -- cannot have default/identity and generated
-CREATE TABLE gtest_err_5a (a int PRIMARY KEY, b int DEFAULT 5 GENERATED ALWAYS AS (a * 2) STORED);
-CREATE TABLE gtest_err_5b (a int PRIMARY KEY, b int GENERATED ALWAYS AS identity GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE gtest_err_5a (a int PRIMARY KEY, b int DEFAULT 5 GENERATED ALWAYS AS (a * 2) VIRTUAL);
+CREATE TABLE gtest_err_5b (a int PRIMARY KEY, b int GENERATED ALWAYS AS identity GENERATED ALWAYS AS (a * 2) VIRTUAL);
 
 -- reference to system column not allowed in generated column
 -- (except tableoid, which we test below)
-CREATE TABLE gtest_err_6a (a int PRIMARY KEY, b bool GENERATED ALWAYS AS (xmin <> 37) STORED);
+CREATE TABLE gtest_err_6a (a int PRIMARY KEY, b bool GENERATED ALWAYS AS (xmin <> 37) VIRTUAL);
 
 -- various prohibited constructs
-CREATE TABLE gtest_err_7a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (avg(a)) STORED);
-CREATE TABLE gtest_err_7b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (row_number() OVER (ORDER BY a)) STORED);
-CREATE TABLE gtest_err_7c (a int PRIMARY KEY, b int GENERATED ALWAYS AS ((SELECT a)) STORED);
-CREATE TABLE gtest_err_7d (a int PRIMARY KEY, b int GENERATED ALWAYS AS (generate_series(1, a)) STORED);
+CREATE TABLE gtest_err_7a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (avg(a)) VIRTUAL);
+CREATE TABLE gtest_err_7b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (row_number() OVER (ORDER BY a)) VIRTUAL);
+CREATE TABLE gtest_err_7c (a int PRIMARY KEY, b int GENERATED ALWAYS AS ((SELECT a)) VIRTUAL);
+CREATE TABLE gtest_err_7d (a int PRIMARY KEY, b int GENERATED ALWAYS AS (generate_series(1, a)) VIRTUAL);
 
 -- GENERATED BY DEFAULT not allowed
-CREATE TABLE gtest_err_8 (a int PRIMARY KEY, b int GENERATED BY DEFAULT AS (a * 2) STORED);
+CREATE TABLE gtest_err_8 (a int PRIMARY KEY, b int GENERATED BY DEFAULT AS (a * 2) VIRTUAL);
 
 INSERT INTO gtest1 VALUES (1);
 INSERT INTO gtest1 VALUES (2, DEFAULT);  -- ok
@@ -70,7 +70,7 @@ CREATE TABLE gtest_err_8 (a int PRIMARY KEY, b int GENERATED BY DEFAULT AS (a *
 SELECT a, b, b * 2 AS b2 FROM gtest1 ORDER BY a;
 SELECT a, b FROM gtest1 WHERE b = 4 ORDER BY a;
 
--- test that overflow error happens on write
+-- test that overflow error happens on read
 INSERT INTO gtest1 VALUES (2000000000);
 SELECT * FROM gtest1;
 DELETE FROM gtest1 WHERE a = 2000000000;
@@ -93,8 +93,8 @@ CREATE TABLE gtestm (
   id int PRIMARY KEY,
   f1 int,
   f2 int,
-  f3 int GENERATED ALWAYS AS (f1 * 2) STORED,
-  f4 int GENERATED ALWAYS AS (f2 * 2) STORED
+  f3 int GENERATED ALWAYS AS (f1 * 2) VIRTUAL,
+  f4 int GENERATED ALWAYS AS (f2 * 2) VIRTUAL
 );
 INSERT INTO gtestm VALUES (1, 5, 100);
 MERGE INTO gtestm t USING (VALUES (1, 10), (2, 20)) v(id, f1) ON t.id = v.id
@@ -134,22 +134,22 @@ CREATE TABLE gtest1_1 () INHERITS (gtest1);
 
 -- can't have generated column that is a child of normal column
 CREATE TABLE gtest_normal (a int, b int);
-CREATE TABLE gtest_normal_child (a int, b int GENERATED ALWAYS AS (a * 2) STORED) INHERITS (gtest_normal);  -- error
-CREATE TABLE gtest_normal_child (a int, b int GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE gtest_normal_child (a int, b int GENERATED ALWAYS AS (a * 2) VIRTUAL) INHERITS (gtest_normal);  -- error
+CREATE TABLE gtest_normal_child (a int, b int GENERATED ALWAYS AS (a * 2) VIRTUAL);
 ALTER TABLE gtest_normal_child INHERIT gtest_normal;  -- error
 DROP TABLE gtest_normal, gtest_normal_child;
 
 -- test inheritance mismatches between parent and child
 CREATE TABLE gtestx (x int, b int DEFAULT 10) INHERITS (gtest1);  -- error
 CREATE TABLE gtestx (x int, b int GENERATED ALWAYS AS IDENTITY) INHERITS (gtest1);  -- error
-CREATE TABLE gtestx (x int, b int GENERATED ALWAYS AS (a * 22) STORED) INHERITS (gtest1);  -- ok, overrides parent
+CREATE TABLE gtestx (x int, b int GENERATED ALWAYS AS (a * 22) VIRTUAL) INHERITS (gtest1);  -- ok, overrides parent
 \d+ gtestx
 
 CREATE TABLE gtestxx_1 (a int NOT NULL, b int);
 ALTER TABLE gtestxx_1 INHERIT gtest1;  -- error
-CREATE TABLE gtestxx_3 (a int NOT NULL, b int GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE gtestxx_3 (a int NOT NULL, b int GENERATED ALWAYS AS (a * 2) VIRTUAL);
 ALTER TABLE gtestxx_3 INHERIT gtest1;  -- ok
-CREATE TABLE gtestxx_4 (b int GENERATED ALWAYS AS (a * 2) STORED, a int NOT NULL);
+CREATE TABLE gtestxx_4 (b int GENERATED ALWAYS AS (a * 2) VIRTUAL, a int NOT NULL);
 ALTER TABLE gtestxx_4 INHERIT gtest1;  -- ok
 
 -- test multiple inheritance mismatches
@@ -161,28 +161,28 @@ CREATE TABLE gtesty (x int, b int);
 CREATE TABLE gtest1_y () INHERITS (gtest1, gtesty);  -- error
 DROP TABLE gtesty;
 
-CREATE TABLE gtesty (x int, b int GENERATED ALWAYS AS (x * 22) STORED);
+CREATE TABLE gtesty (x int, b int GENERATED ALWAYS AS (x * 22) VIRTUAL);
 CREATE TABLE gtest1_y () INHERITS (gtest1, gtesty);  -- error
-CREATE TABLE gtest1_y (b int GENERATED ALWAYS AS (x + 1) STORED) INHERITS (gtest1, gtesty);  -- ok
+CREATE TABLE gtest1_y (b int GENERATED ALWAYS AS (x + 1) VIRTUAL) INHERITS (gtest1, gtesty);  -- ok
 \d gtest1_y
 
 -- test correct handling of GENERATED column that's only in child
 CREATE TABLE gtestp (f1 int);
-CREATE TABLE gtestc (f2 int GENERATED ALWAYS AS (f1+1) STORED) INHERITS(gtestp);
+CREATE TABLE gtestc (f2 int GENERATED ALWAYS AS (f1+1) VIRTUAL) INHERITS(gtestp);
 INSERT INTO gtestc values(42);
 TABLE gtestc;
 UPDATE gtestp SET f1 = f1 * 10;
 TABLE gtestc;
 DROP TABLE gtestp CASCADE;
 
--- test stored update
-CREATE TABLE gtest3 (a int, b int GENERATED ALWAYS AS (a * 3) STORED);
+-- test update XXX
+CREATE TABLE gtest3 (a int, b int GENERATED ALWAYS AS (a * 3) VIRTUAL);
 INSERT INTO gtest3 (a) VALUES (1), (2), (3), (NULL);
 SELECT * FROM gtest3 ORDER BY a;
 UPDATE gtest3 SET a = 22 WHERE a = 2;
 SELECT * FROM gtest3 ORDER BY a;
 
-CREATE TABLE gtest3a (a text, b text GENERATED ALWAYS AS (a || '+' || a) STORED);
+CREATE TABLE gtest3a (a text, b text GENERATED ALWAYS AS (a || '+' || a) VIRTUAL);
 INSERT INTO gtest3a (a) VALUES ('a'), ('b'), ('c'), (NULL);
 SELECT * FROM gtest3a ORDER BY a;
 UPDATE gtest3a SET a = 'bb' WHERE a = 'b';
@@ -222,12 +222,12 @@ CREATE TABLE gtest3a (a text, b text GENERATED ALWAYS AS (a || '+' || a) STORED)
 SELECT * FROM gtest3 ORDER BY a;
 
 -- null values
-CREATE TABLE gtest2 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (NULL) STORED);
+CREATE TABLE gtest2 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (NULL) VIRTUAL);
 INSERT INTO gtest2 VALUES (1);
 SELECT * FROM gtest2;
 
 -- simple column reference for varlena types
-CREATE TABLE gtest_varlena (a varchar, b varchar GENERATED ALWAYS AS (a) STORED);
+CREATE TABLE gtest_varlena (a varchar, b varchar GENERATED ALWAYS AS (a) VIRTUAL);
 INSERT INTO gtest_varlena (a) VALUES('01234567890123456789');
 INSERT INTO gtest_varlena (a) VALUES(NULL);
 SELECT * FROM gtest_varlena ORDER BY a;
@@ -237,7 +237,7 @@ CREATE TABLE gtest_varlena (a varchar, b varchar GENERATED ALWAYS AS (a) STORED)
 CREATE TYPE double_int as (a int, b int);
 CREATE TABLE gtest4 (
     a int,
-    b double_int GENERATED ALWAYS AS ((a * 2, a * 3)) STORED
+    b double_int GENERATED ALWAYS AS ((a * 2, a * 3)) VIRTUAL
 );
 INSERT INTO gtest4 VALUES (1), (6);
 SELECT * FROM gtest4;
@@ -248,168 +248,168 @@ CREATE TABLE gtest4 (
 -- using tableoid is allowed
 CREATE TABLE gtest_tableoid (
   a int PRIMARY KEY,
-  b bool GENERATED ALWAYS AS (tableoid = 'gtest_tableoid'::regclass) STORED
+  b bool GENERATED ALWAYS AS (tableoid = 'gtest_tableoid'::regclass) VIRTUAL
 );
 INSERT INTO gtest_tableoid VALUES (1), (2);
 ALTER TABLE gtest_tableoid ADD COLUMN
-  c regclass GENERATED ALWAYS AS (tableoid) STORED;
+  c regclass GENERATED ALWAYS AS (tableoid) VIRTUAL;
 SELECT * FROM gtest_tableoid;
 
 -- drop column behavior
-CREATE TABLE gtest10 (a int PRIMARY KEY, b int, c int GENERATED ALWAYS AS (b * 2) STORED);
+CREATE TABLE gtest10 (a int PRIMARY KEY, b int, c int GENERATED ALWAYS AS (b * 2) VIRTUAL);
 ALTER TABLE gtest10 DROP COLUMN b;  -- fails
 ALTER TABLE gtest10 DROP COLUMN b CASCADE;  -- drops c too
 
 \d gtest10
 
-CREATE TABLE gtest10a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE gtest10a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL);
 ALTER TABLE gtest10a DROP COLUMN b;
 INSERT INTO gtest10a (a) VALUES (1);
 
 -- privileges
 CREATE USER regress_user11;
 
-CREATE TABLE gtest11s (a int PRIMARY KEY, b int, c int GENERATED ALWAYS AS (b * 2) STORED);
-INSERT INTO gtest11s VALUES (1, 10), (2, 20);
-GRANT SELECT (a, c) ON gtest11s TO regress_user11;
+CREATE TABLE gtest11v (a int PRIMARY KEY, b int, c int GENERATED ALWAYS AS (b * 2) VIRTUAL);
+INSERT INTO gtest11v VALUES (1, 10), (2, 20);
+GRANT SELECT (a, c) ON gtest11v TO regress_user11;
 
 CREATE FUNCTION gf1(a int) RETURNS int AS $$ SELECT a * 3 $$ IMMUTABLE LANGUAGE SQL;
 REVOKE ALL ON FUNCTION gf1(int) FROM PUBLIC;
 
-CREATE TABLE gtest12s (a int PRIMARY KEY, b int, c int GENERATED ALWAYS AS (gf1(b)) STORED);
-INSERT INTO gtest12s VALUES (1, 10), (2, 20);
+CREATE TABLE gtest12v (a int PRIMARY KEY, b int, c int GENERATED ALWAYS AS (gf1(b)) VIRTUAL);
+INSERT INTO gtest12v VALUES (1, 10), (2, 20);
 GRANT SELECT (a, c) ON gtest12s TO regress_user11;
 
 SET ROLE regress_user11;
-SELECT a, b FROM gtest11s;  -- not allowed
-SELECT a, c FROM gtest11s;  -- allowed
+SELECT a, b FROM gtest11v;  -- not allowed
+SELECT a, c FROM gtest11v;  -- allowed
 SELECT gf1(10);  -- not allowed
-SELECT a, c FROM gtest12s;  -- allowed
+SELECT a, c FROM gtest12v;  -- not allowed; TODO: ought to be allowed
 RESET ROLE;
 
 DROP FUNCTION gf1(int);  -- fail
-DROP TABLE gtest11s, gtest12s;
+DROP TABLE gtest11v, gtest12v;
 DROP FUNCTION gf1(int);
 DROP USER regress_user11;
 
 -- check constraints
-CREATE TABLE gtest20 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED CHECK (b < 50));
+CREATE TABLE gtest20 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL CHECK (b < 50));
 INSERT INTO gtest20 (a) VALUES (10);  -- ok
 INSERT INTO gtest20 (a) VALUES (30);  -- violates constraint
 
 ALTER TABLE gtest20 ALTER COLUMN b SET EXPRESSION AS (a * 100);  -- violates constraint
 ALTER TABLE gtest20 ALTER COLUMN b SET EXPRESSION AS (a * 3);  -- ok
 
-CREATE TABLE gtest20a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE gtest20a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL);
 INSERT INTO gtest20a (a) VALUES (10);
 INSERT INTO gtest20a (a) VALUES (30);
 ALTER TABLE gtest20a ADD CHECK (b < 50);  -- fails on existing row
 
-CREATE TABLE gtest20b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE gtest20b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL);
 INSERT INTO gtest20b (a) VALUES (10);
 INSERT INTO gtest20b (a) VALUES (30);
 ALTER TABLE gtest20b ADD CONSTRAINT chk CHECK (b < 50) NOT VALID;
 ALTER TABLE gtest20b VALIDATE CONSTRAINT chk;  -- fails on existing row
 
 -- not-null constraints
-CREATE TABLE gtest21a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (nullif(a, 0)) STORED NOT NULL);
+CREATE TABLE gtest21a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (nullif(a, 0)) VIRTUAL NOT NULL);
 INSERT INTO gtest21a (a) VALUES (1);  -- ok
 INSERT INTO gtest21a (a) VALUES (0);  -- violates constraint
 
-CREATE TABLE gtest21b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (nullif(a, 0)) STORED);
-ALTER TABLE gtest21b ALTER COLUMN b SET NOT NULL;
+CREATE TABLE gtest21b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (nullif(a, 0)) VIRTUAL);
+ALTER TABLE gtest21b ALTER COLUMN b SET NOT NULL;  -- FIXME
 INSERT INTO gtest21b (a) VALUES (1);  -- ok
 INSERT INTO gtest21b (a) VALUES (0);  -- violates constraint
-ALTER TABLE gtest21b ALTER COLUMN b DROP NOT NULL;
+ALTER TABLE gtest21b ALTER COLUMN b DROP NOT NULL;  -- FIXME
 INSERT INTO gtest21b (a) VALUES (0);  -- ok now
 
 -- index constraints
-CREATE TABLE gtest22a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a / 2) STORED UNIQUE);
-INSERT INTO gtest22a VALUES (2);
-INSERT INTO gtest22a VALUES (3);
-INSERT INTO gtest22a VALUES (4);
-CREATE TABLE gtest22b (a int, b int GENERATED ALWAYS AS (a / 2) STORED, PRIMARY KEY (a, b));
-INSERT INTO gtest22b VALUES (2);
-INSERT INTO gtest22b VALUES (2);
+CREATE TABLE gtest22a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a / 2) VIRTUAL UNIQUE);
+--INSERT INTO gtest22a VALUES (2);
+--INSERT INTO gtest22a VALUES (3);
+--INSERT INTO gtest22a VALUES (4);
+CREATE TABLE gtest22b (a int, b int GENERATED ALWAYS AS (a / 2) VIRTUAL, PRIMARY KEY (a, b));
+--INSERT INTO gtest22b VALUES (2);
+--INSERT INTO gtest22b VALUES (2);
 
 -- indexes
-CREATE TABLE gtest22c (a int, b int GENERATED ALWAYS AS (a * 2) STORED);
-CREATE INDEX gtest22c_b_idx ON gtest22c (b);
-CREATE INDEX gtest22c_expr_idx ON gtest22c ((b * 3));
-CREATE INDEX gtest22c_pred_idx ON gtest22c (a) WHERE b > 0;
-\d gtest22c
-
-INSERT INTO gtest22c VALUES (1), (2), (3);
-SET enable_seqscan TO off;
-SET enable_bitmapscan TO off;
-EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b = 4;
-SELECT * FROM gtest22c WHERE b = 4;
-EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b * 3 = 6;
-SELECT * FROM gtest22c WHERE b * 3 = 6;
-EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
-SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
-
-ALTER TABLE gtest22c ALTER COLUMN b SET EXPRESSION AS (a * 4);
-ANALYZE gtest22c;
-EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b = 8;
-SELECT * FROM gtest22c WHERE b = 8;
-EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b * 3 = 12;
-SELECT * FROM gtest22c WHERE b * 3 = 12;
-EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
-SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
-RESET enable_seqscan;
-RESET enable_bitmapscan;
+CREATE TABLE gtest22c (a int, b int GENERATED ALWAYS AS (a * 2) VIRTUAL);
+--CREATE INDEX gtest22c_b_idx ON gtest22c (b);
+--CREATE INDEX gtest22c_expr_idx ON gtest22c ((b * 3));
+--CREATE INDEX gtest22c_pred_idx ON gtest22c (a) WHERE b > 0;
+--\d gtest22c
+
+--INSERT INTO gtest22c VALUES (1), (2), (3);
+--SET enable_seqscan TO off;
+--SET enable_bitmapscan TO off;
+--EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b = 4;
+--SELECT * FROM gtest22c WHERE b = 4;
+--EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b * 3 = 6;
+--SELECT * FROM gtest22c WHERE b * 3 = 6;
+--EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
+--SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
+
+--ALTER TABLE gtest22c ALTER COLUMN b SET EXPRESSION AS (a * 4);
+--ANALYZE gtest22c;
+--EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b = 8;
+--SELECT * FROM gtest22c WHERE b = 8;
+--EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b * 3 = 12;
+--SELECT * FROM gtest22c WHERE b * 3 = 12;
+--EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
+--SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
+--RESET enable_seqscan;
+--RESET enable_bitmapscan;
 
 -- foreign keys
 CREATE TABLE gtest23a (x int PRIMARY KEY, y int);
-INSERT INTO gtest23a VALUES (1, 11), (2, 22), (3, 33);
+--INSERT INTO gtest23a VALUES (1, 11), (2, 22), (3, 33);
 
-CREATE TABLE gtest23x (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED REFERENCES gtest23a (x) ON UPDATE CASCADE);  -- error
-CREATE TABLE gtest23x (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED REFERENCES gtest23a (x) ON DELETE SET NULL);  -- error
+CREATE TABLE gtest23x (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL REFERENCES gtest23a (x) ON UPDATE CASCADE);  -- error
+CREATE TABLE gtest23x (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL REFERENCES gtest23a (x) ON DELETE SET NULL);  -- error
 
-CREATE TABLE gtest23b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED REFERENCES gtest23a (x));
-\d gtest23b
+CREATE TABLE gtest23b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL REFERENCES gtest23a (x));
+--\d gtest23b
 
-INSERT INTO gtest23b VALUES (1);  -- ok
-INSERT INTO gtest23b VALUES (5);  -- error
-ALTER TABLE gtest23b ALTER COLUMN b SET EXPRESSION AS (a * 5); -- error
-ALTER TABLE gtest23b ALTER COLUMN b SET EXPRESSION AS (a * 1); -- ok
+--INSERT INTO gtest23b VALUES (1);  -- ok
+--INSERT INTO gtest23b VALUES (5);  -- error
+--ALTER TABLE gtest23b ALTER COLUMN b SET EXPRESSION AS (a * 5); -- error
+--ALTER TABLE gtest23b ALTER COLUMN b SET EXPRESSION AS (a * 1); -- ok
 
-DROP TABLE gtest23b;
-DROP TABLE gtest23a;
+--DROP TABLE gtest23b;
+--DROP TABLE gtest23a;
 
-CREATE TABLE gtest23p (x int, y int GENERATED ALWAYS AS (x * 2) STORED, PRIMARY KEY (y));
-INSERT INTO gtest23p VALUES (1), (2), (3);
+CREATE TABLE gtest23p (x int, y int GENERATED ALWAYS AS (x * 2) VIRTUAL, PRIMARY KEY (y));
+--INSERT INTO gtest23p VALUES (1), (2), (3);
 
 CREATE TABLE gtest23q (a int PRIMARY KEY, b int REFERENCES gtest23p (y));
-INSERT INTO gtest23q VALUES (1, 2);  -- ok
-INSERT INTO gtest23q VALUES (2, 5);  -- error
+--INSERT INTO gtest23q VALUES (1, 2);  -- ok
+--INSERT INTO gtest23q VALUES (2, 5);  -- error
 
 -- domains
 CREATE DOMAIN gtestdomain1 AS int CHECK (VALUE < 10);
-CREATE TABLE gtest24 (a int PRIMARY KEY, b gtestdomain1 GENERATED ALWAYS AS (a * 2) STORED);
-INSERT INTO gtest24 (a) VALUES (4);  -- ok
-INSERT INTO gtest24 (a) VALUES (6);  -- error
+CREATE TABLE gtest24 (a int PRIMARY KEY, b gtestdomain1 GENERATED ALWAYS AS (a * 2) VIRTUAL);
+--INSERT INTO gtest24 (a) VALUES (4);  -- ok
+--INSERT INTO gtest24 (a) VALUES (6);  -- error
 
 -- typed tables (currently not supported)
 CREATE TYPE gtest_type AS (f1 integer, f2 text, f3 bigint);
-CREATE TABLE gtest28 OF gtest_type (f1 WITH OPTIONS GENERATED ALWAYS AS (f2 *2) STORED);
+CREATE TABLE gtest28 OF gtest_type (f1 WITH OPTIONS GENERATED ALWAYS AS (f2 *2) VIRTUAL);
 DROP TYPE gtest_type CASCADE;
 
 -- partitioning cases
 CREATE TABLE gtest_parent (f1 date NOT NULL, f2 bigint, f3 bigint) PARTITION BY RANGE (f1);
 CREATE TABLE gtest_child PARTITION OF gtest_parent (
-    f3 WITH OPTIONS GENERATED ALWAYS AS (f2 * 2) STORED
+    f3 WITH OPTIONS GENERATED ALWAYS AS (f2 * 2) VIRTUAL
 ) FOR VALUES FROM ('2016-07-01') TO ('2016-08-01'); -- error
-CREATE TABLE gtest_child (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) STORED);
+CREATE TABLE gtest_child (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) VIRTUAL);
 ALTER TABLE gtest_parent ATTACH PARTITION gtest_child FOR VALUES FROM ('2016-07-01') TO ('2016-08-01'); -- error
 DROP TABLE gtest_parent, gtest_child;
 
-CREATE TABLE gtest_parent (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE (f1);
+CREATE TABLE gtest_parent (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) VIRTUAL) PARTITION BY RANGE (f1);
 CREATE TABLE gtest_child PARTITION OF gtest_parent
   FOR VALUES FROM ('2016-07-01') TO ('2016-08-01');  -- inherits gen expr
 CREATE TABLE gtest_child2 PARTITION OF gtest_parent (
-    f3 WITH OPTIONS GENERATED ALWAYS AS (f2 * 22) STORED  -- overrides gen expr
+    f3 WITH OPTIONS GENERATED ALWAYS AS (f2 * 22) VIRTUAL  -- overrides gen expr
 ) FOR VALUES FROM ('2016-08-01') TO ('2016-09-01');
 CREATE TABLE gtest_child3 PARTITION OF gtest_parent (
     f3 DEFAULT 42  -- error
@@ -426,7 +426,7 @@ CREATE TABLE gtest_child3 (f1 date NOT NULL, f2 bigint, f3 bigint DEFAULT 42);
 CREATE TABLE gtest_child3 (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS IDENTITY);
 ALTER TABLE gtest_parent ATTACH PARTITION gtest_child3 FOR VALUES FROM ('2016-09-01') TO ('2016-10-01'); -- error
 DROP TABLE gtest_child3;
-CREATE TABLE gtest_child3 (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 33) STORED);
+CREATE TABLE gtest_child3 (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 33) VIRTUAL);
 ALTER TABLE gtest_parent ATTACH PARTITION gtest_child3 FOR VALUES FROM ('2016-09-01') TO ('2016-10-01');
 \d gtest_child
 \d gtest_child2
@@ -457,21 +457,21 @@ CREATE TABLE gtest_child3 (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWA
 -- we leave these tables around for purposes of testing dump/reload/upgrade
 
 -- generated columns in partition key (not allowed)
-CREATE TABLE gtest_part_key (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE (f3);
-CREATE TABLE gtest_part_key (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE ((f3 * 3));
+CREATE TABLE gtest_part_key (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) VIRTUAL) PARTITION BY RANGE (f3);
+CREATE TABLE gtest_part_key (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) VIRTUAL) PARTITION BY RANGE ((f3 * 3));
 
 -- ALTER TABLE ... ADD COLUMN
 CREATE TABLE gtest25 (a int PRIMARY KEY);
 INSERT INTO gtest25 VALUES (3), (4);
-ALTER TABLE gtest25 ADD COLUMN b int GENERATED ALWAYS AS (a * 2) STORED, ALTER COLUMN b SET EXPRESSION AS (a * 3);
+ALTER TABLE gtest25 ADD COLUMN b int GENERATED ALWAYS AS (a * 2) VIRTUAL, ALTER COLUMN b SET EXPRESSION AS (a * 3);
 SELECT * FROM gtest25 ORDER BY a;
-ALTER TABLE gtest25 ADD COLUMN x int GENERATED ALWAYS AS (b * 4) STORED;  -- error
-ALTER TABLE gtest25 ADD COLUMN x int GENERATED ALWAYS AS (z * 4) STORED;  -- error
+ALTER TABLE gtest25 ADD COLUMN x int GENERATED ALWAYS AS (b * 4) VIRTUAL;  -- error
+ALTER TABLE gtest25 ADD COLUMN x int GENERATED ALWAYS AS (z * 4) VIRTUAL;  -- error
 ALTER TABLE gtest25 ADD COLUMN c int DEFAULT 42,
-  ADD COLUMN x int GENERATED ALWAYS AS (c * 4) STORED;
+  ADD COLUMN x int GENERATED ALWAYS AS (c * 4) VIRTUAL;
 ALTER TABLE gtest25 ADD COLUMN d int DEFAULT 101;
 ALTER TABLE gtest25 ALTER COLUMN d SET DATA TYPE float8,
-  ADD COLUMN y float8 GENERATED ALWAYS AS (d * 4) STORED;
+  ADD COLUMN y float8 GENERATED ALWAYS AS (d * 4) VIRTUAL;
 SELECT * FROM gtest25 ORDER BY a;
 \d gtest25
 
@@ -479,7 +479,7 @@ CREATE TABLE gtest25 (a int PRIMARY KEY);
 CREATE TABLE gtest27 (
     a int,
     b int,
-    x int GENERATED ALWAYS AS ((a + b) * 2) STORED
+    x int GENERATED ALWAYS AS ((a + b) * 2) VIRTUAL
 );
 INSERT INTO gtest27 (a, b) VALUES (3, 7), (4, 11);
 ALTER TABLE gtest27 ALTER COLUMN a TYPE text;  -- error
@@ -493,7 +493,7 @@ CREATE TABLE gtest27 (
   DROP COLUMN x,
   ALTER COLUMN a TYPE bigint,
   ALTER COLUMN b TYPE bigint,
-  ADD COLUMN x bigint GENERATED ALWAYS AS ((a + b) * 2) STORED;
+  ADD COLUMN x bigint GENERATED ALWAYS AS ((a + b) * 2) VIRTUAL;
 \d gtest27
 -- Ideally you could just do this, but not today (and should x change type?):
 ALTER TABLE gtest27
@@ -505,7 +505,7 @@ CREATE TABLE gtest27 (
 -- ALTER TABLE ... ALTER COLUMN ... DROP EXPRESSION
 CREATE TABLE gtest29 (
     a int,
-    b int GENERATED ALWAYS AS (a * 2) STORED
+    b int GENERATED ALWAYS AS (a * 2) VIRTUAL
 );
 INSERT INTO gtest29 (a) VALUES (3), (4);
 SELECT * FROM gtest29;
@@ -532,7 +532,7 @@ CREATE TABLE gtest29 (
 -- with inheritance
 CREATE TABLE gtest30 (
     a int,
-    b int GENERATED ALWAYS AS (a * 2) STORED
+    b int GENERATED ALWAYS AS (a * 2) VIRTUAL
 );
 CREATE TABLE gtest30_1 () INHERITS (gtest30);
 ALTER TABLE gtest30 ALTER COLUMN b DROP EXPRESSION;
@@ -541,7 +541,7 @@ CREATE TABLE gtest30_1 () INHERITS (gtest30);
 DROP TABLE gtest30 CASCADE;
 CREATE TABLE gtest30 (
     a int,
-    b int GENERATED ALWAYS AS (a * 2) STORED
+    b int GENERATED ALWAYS AS (a * 2) VIRTUAL
 );
 CREATE TABLE gtest30_1 () INHERITS (gtest30);
 ALTER TABLE ONLY gtest30 ALTER COLUMN b DROP EXPRESSION;  -- error
@@ -552,7 +552,7 @@ CREATE TABLE gtest30_1 () INHERITS (gtest30);
 -- triggers
 CREATE TABLE gtest26 (
     a int PRIMARY KEY,
-    b int GENERATED ALWAYS AS (a * 2) STORED
+    b int GENERATED ALWAYS AS (a * 2) VIRTUAL
 );
 
 CREATE FUNCTION gtest_trigger_func() RETURNS trigger
@@ -614,6 +614,9 @@ CREATE TRIGGER gtest4 AFTER INSERT OR UPDATE ON gtest26
 DROP TRIGGER gtest2 ON gtest26;
 DROP TRIGGER gtest3 ON gtest26;
 
+-- check disallowed modification of virtual columns
+-- TODO
+
 -- Check that an UPDATE of "a" fires the trigger for UPDATE OF b, per
 -- SQL standard.
 CREATE FUNCTION gtest_trigger_func3() RETURNS trigger
@@ -667,7 +670,7 @@ CREATE TABLE gtest28a (
   a int,
   b int,
   c int,
-  x int GENERATED ALWAYS AS (b * 2) STORED
+  x int GENERATED ALWAYS AS (b * 2) VIRTUAL
 );
 
 ALTER TABLE gtest28a DROP COLUMN a;
diff --git a/src/test/subscription/t/011_generated.pl b/src/test/subscription/t/011_generated.pl
index 8b2e5f4708e..faee155daa7 100644
--- a/src/test/subscription/t/011_generated.pl
+++ b/src/test/subscription/t/011_generated.pl
@@ -21,11 +21,11 @@
 my $publisher_connstr = $node_publisher->connstr . ' dbname=postgres';
 
 $node_publisher->safe_psql('postgres',
-	"CREATE TABLE tab1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED)"
+	"CREATE TABLE tab1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED, c int GENERATED ALWAYS AS (a * 3) VIRTUAL)"
 );
 
 $node_subscriber->safe_psql('postgres',
-	"CREATE TABLE tab1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 22) STORED, c int)"
+	"CREATE TABLE tab1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 22) STORED, c int GENERATED ALWAYS AS (a * 33) VIRTUAL, d int)"
 );
 
 # data for initial sync
@@ -42,10 +42,10 @@
 # Wait for initial sync of all subscriptions
 $node_subscriber->wait_for_subscription_sync;
 
-my $result = $node_subscriber->safe_psql('postgres', "SELECT a, b FROM tab1");
-is( $result, qq(1|22
-2|44
-3|66), 'generated columns initial sync');
+my $result = $node_subscriber->safe_psql('postgres', "SELECT a, b, c FROM tab1");
+is( $result, qq(1|22|33
+2|44|66
+3|66|99), 'generated columns initial sync');
 
 # data to replicate
 
@@ -56,11 +56,11 @@
 $node_publisher->wait_for_catchup('sub1');
 
 $result = $node_subscriber->safe_psql('postgres', "SELECT * FROM tab1");
-is( $result, qq(1|22|
-2|44|
-3|66|
-4|88|
-6|132|), 'generated columns replicated');
+is( $result, qq(1|22|33|
+2|44|66|
+3|66|99|
+4|88|132|
+6|132|198|), 'generated columns replicated');
 
 # try it with a subscriber-side trigger
 
@@ -69,7 +69,7 @@
 CREATE FUNCTION tab1_trigger_func() RETURNS trigger
 LANGUAGE plpgsql AS $$
 BEGIN
-  NEW.c := NEW.a + 10;
+  NEW.d := NEW.a + 10;
   RETURN NEW;
 END $$;
 
@@ -88,12 +88,12 @@ BEGIN
 
 $result =
   $node_subscriber->safe_psql('postgres', "SELECT * FROM tab1 ORDER BY 1");
-is( $result, qq(1|22|
-2|44|
-3|66|
-4|88|
-6|132|
-8|176|18
-9|198|19), 'generated columns replicated with trigger');
+is( $result, qq(1|22|33|
+2|44|66|
+3|66|99|
+4|88|132|
+6|132|198|
+8|176|264|18
+9|198|297|19), 'generated columns replicated with trigger');
 
 done_testing();
-- 
2.44.0



Attachments:

  [text/plain] v0-0001-Rename-regress-test-generated-to-generated_stored.patch (2.0K, ../../[email protected]/2-v0-0001-Rename-regress-test-generated-to-generated_stored.patch)
  download | inline diff:
From 287a20948056b42884b4ee0f5835f1b618ae2ed7 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <[email protected]>
Date: Mon, 29 Apr 2024 09:46:43 +0200
Subject: [PATCH v0 1/5] Rename regress test generated to generated_stored

This makes naming room to have another test file for virtual generated
columns.
---
 .../regress/expected/{generated.out => generated_stored.out}    | 0
 src/test/regress/parallel_schedule                              | 2 +-
 src/test/regress/sql/{generated.sql => generated_stored.sql}    | 0
 3 files changed, 1 insertion(+), 1 deletion(-)
 rename src/test/regress/expected/{generated.out => generated_stored.out} (100%)
 rename src/test/regress/sql/{generated.sql => generated_stored.sql} (100%)

diff --git a/src/test/regress/expected/generated.out b/src/test/regress/expected/generated_stored.out
similarity index 100%
rename from src/test/regress/expected/generated.out
rename to src/test/regress/expected/generated_stored.out
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index 675c5676171..f345d6b45aa 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -66,7 +66,7 @@ test: select_into select_distinct select_distinct_on select_implicit select_havi
 # ----------
 # Another group of parallel tests
 # ----------
-test: brin gin gist spgist privileges init_privs security_label collate matview lock replica_identity rowsecurity object_address tablesample groupingsets drop_operator password identity generated join_hash
+test: brin gin gist spgist privileges init_privs security_label collate matview lock replica_identity rowsecurity object_address tablesample groupingsets drop_operator password identity generated_stored join_hash
 
 # ----------
 # Additional BRIN tests
diff --git a/src/test/regress/sql/generated.sql b/src/test/regress/sql/generated_stored.sql
similarity index 100%
rename from src/test/regress/sql/generated.sql
rename to src/test/regress/sql/generated_stored.sql

base-commit: 5c9f35fc48ea99e59300a267e090e3eafd1b3b0e
-- 
2.44.0



  [text/plain] v0-0002-Put-generated_stored-test-objects-in-a-schema.patch (18.9K, ../../[email protected]/3-v0-0002-Put-generated_stored-test-objects-in-a-schema.patch)
  download | inline diff:
From 9acecbb3f45fa45522e8a4d2f10c29819d3abf54 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <[email protected]>
Date: Mon, 29 Apr 2024 09:46:43 +0200
Subject: [PATCH v0 2/5] Put generated_stored test objects in a schema

This avoids naming conflicts with concurrent tests with similarly
named objects.  Currently, there are none, but a tests for virtual
generated columns are planned to be added.
---
 .../regress/expected/generated_stored.out     | 71 ++++++++++---------
 src/test/regress/sql/generated_stored.sql     |  8 ++-
 2 files changed, 43 insertions(+), 36 deletions(-)

diff --git a/src/test/regress/expected/generated_stored.out b/src/test/regress/expected/generated_stored.out
index a4f37736623..6682092124c 100644
--- a/src/test/regress/expected/generated_stored.out
+++ b/src/test/regress/expected/generated_stored.out
@@ -4,9 +4,12 @@ SELECT attrelid, attname, attgenerated FROM pg_attribute WHERE attgenerated NOT
 ----------+---------+--------------
 (0 rows)
 
+CREATE SCHEMA generated_stored_tests;
+GRANT USAGE ON SCHEMA generated_stored_tests TO PUBLIC;
+SET search_path = generated_stored_tests;
 CREATE TABLE gtest0 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (55) STORED);
 CREATE TABLE gtest1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED);
-SELECT table_name, column_name, column_default, is_nullable, is_generated, generation_expression FROM information_schema.columns WHERE table_name LIKE 'gtest_' ORDER BY 1, 2;
+SELECT table_name, column_name, column_default, is_nullable, is_generated, generation_expression FROM information_schema.columns WHERE table_schema = 'generated_stored_tests' ORDER BY 1, 2;
  table_name | column_name | column_default | is_nullable | is_generated | generation_expression 
 ------------+-------------+----------------+-------------+--------------+-----------------------
  gtest0     | a           |                | NO          | NEVER        | 
@@ -15,14 +18,14 @@ SELECT table_name, column_name, column_default, is_nullable, is_generated, gener
  gtest1     | b           |                | YES         | ALWAYS       | (a * 2)
 (4 rows)
 
-SELECT table_name, column_name, dependent_column FROM information_schema.column_column_usage ORDER BY 1, 2, 3;
+SELECT table_name, column_name, dependent_column FROM information_schema.column_column_usage WHERE table_schema = 'generated_stored_tests' ORDER BY 1, 2, 3;
  table_name | column_name | dependent_column 
 ------------+-------------+------------------
  gtest1     | a           | b
 (1 row)
 
 \d gtest1
-                            Table "public.gtest1"
+                    Table "generated_stored_tests.gtest1"
  Column |  Type   | Collation | Nullable |              Default               
 --------+---------+-----------+----------+------------------------------------
  a      | integer |           | not null | 
@@ -270,7 +273,7 @@ SELECT * FROM gtest1_1;
 (0 rows)
 
 \d gtest1_1
-                           Table "public.gtest1_1"
+                   Table "generated_stored_tests.gtest1_1"
  Column |  Type   | Collation | Nullable |              Default               
 --------+---------+-----------+----------+------------------------------------
  a      | integer |           | not null | 
@@ -312,7 +315,7 @@ ERROR:  column "b" inherits from generated column but specifies identity
 CREATE TABLE gtestx (x int, b int GENERATED ALWAYS AS (a * 22) STORED) INHERITS (gtest1);  -- ok, overrides parent
 NOTICE:  merging column "b" with inherited definition
 \d+ gtestx
-                                                Table "public.gtestx"
+                                        Table "generated_stored_tests.gtestx"
  Column |  Type   | Collation | Nullable |               Default               | Storage | Stats target | Description 
 --------+---------+-----------+----------+-------------------------------------+---------+--------------+-------------
  a      | integer |           | not null |                                     | plain   |              | 
@@ -350,7 +353,7 @@ NOTICE:  merging multiple inherited definitions of column "b"
 NOTICE:  moving and merging column "b" with inherited definition
 DETAIL:  User-specified column moved to the position of the inherited column.
 \d gtest1_y
-                           Table "public.gtest1_y"
+                   Table "generated_stored_tests.gtest1_y"
  Column |  Type   | Collation | Nullable |              Default               
 --------+---------+-----------+----------+------------------------------------
  a      | integer |           | not null | 
@@ -525,7 +528,7 @@ HINT:  Use DROP ... CASCADE to drop the dependent objects too.
 ALTER TABLE gtest10 DROP COLUMN b CASCADE;  -- drops c too
 NOTICE:  drop cascades to column c of table gtest10
 \d gtest10
-              Table "public.gtest10"
+      Table "generated_stored_tests.gtest10"
  Column |  Type   | Collation | Nullable | Default 
 --------+---------+-----------+----------+---------
  a      | integer |           | not null | 
@@ -624,7 +627,7 @@ CREATE INDEX gtest22c_b_idx ON gtest22c (b);
 CREATE INDEX gtest22c_expr_idx ON gtest22c ((b * 3));
 CREATE INDEX gtest22c_pred_idx ON gtest22c (a) WHERE b > 0;
 \d gtest22c
-                           Table "public.gtest22c"
+                   Table "generated_stored_tests.gtest22c"
  Column |  Type   | Collation | Nullable |              Default               
 --------+---------+-----------+----------+------------------------------------
  a      | integer |           |          | 
@@ -728,7 +731,7 @@ CREATE TABLE gtest23x (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STOR
 ERROR:  invalid ON DELETE action for foreign key constraint containing generated column
 CREATE TABLE gtest23b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED REFERENCES gtest23a (x));
 \d gtest23b
-                           Table "public.gtest23b"
+                   Table "generated_stored_tests.gtest23b"
  Column |  Type   | Collation | Nullable |              Default               
 --------+---------+-----------+----------+------------------------------------
  a      | integer |           | not null | 
@@ -807,7 +810,7 @@ DROP TABLE gtest_child3;
 CREATE TABLE gtest_child3 (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 33) STORED);
 ALTER TABLE gtest_parent ATTACH PARTITION gtest_child3 FOR VALUES FROM ('2016-09-01') TO ('2016-10-01');
 \d gtest_child
-                          Table "public.gtest_child"
+                  Table "generated_stored_tests.gtest_child"
  Column |  Type  | Collation | Nullable |               Default               
 --------+--------+-----------+----------+-------------------------------------
  f1     | date   |           | not null | 
@@ -816,7 +819,7 @@ ALTER TABLE gtest_parent ATTACH PARTITION gtest_child3 FOR VALUES FROM ('2016-09
 Partition of: gtest_parent FOR VALUES FROM ('07-01-2016') TO ('08-01-2016')
 
 \d gtest_child2
-                          Table "public.gtest_child2"
+                  Table "generated_stored_tests.gtest_child2"
  Column |  Type  | Collation | Nullable |               Default                
 --------+--------+-----------+----------+--------------------------------------
  f1     | date   |           | not null | 
@@ -825,7 +828,7 @@ Partition of: gtest_parent FOR VALUES FROM ('07-01-2016') TO ('08-01-2016')
 Partition of: gtest_parent FOR VALUES FROM ('08-01-2016') TO ('09-01-2016')
 
 \d gtest_child3
-                          Table "public.gtest_child3"
+                  Table "generated_stored_tests.gtest_child3"
  Column |  Type  | Collation | Nullable |               Default                
 --------+--------+-----------+----------+--------------------------------------
  f1     | date   |           | not null | 
@@ -857,7 +860,7 @@ SELECT tableoid::regclass, * FROM gtest_parent ORDER BY 1, 2, 3;
 ALTER TABLE ONLY gtest_parent ALTER COLUMN f3 SET EXPRESSION AS (f2 * 4);
 ALTER TABLE gtest_child ALTER COLUMN f3 SET EXPRESSION AS (f2 * 10);
 \d gtest_parent
-                   Partitioned table "public.gtest_parent"
+           Partitioned table "generated_stored_tests.gtest_parent"
  Column |  Type  | Collation | Nullable |               Default               
 --------+--------+-----------+----------+-------------------------------------
  f1     | date   |           | not null | 
@@ -867,7 +870,7 @@ Partition key: RANGE (f1)
 Number of partitions: 3 (Use \d+ to list them.)
 
 \d gtest_child
-                          Table "public.gtest_child"
+                  Table "generated_stored_tests.gtest_child"
  Column |  Type  | Collation | Nullable |               Default                
 --------+--------+-----------+----------+--------------------------------------
  f1     | date   |           | not null | 
@@ -876,7 +879,7 @@ Number of partitions: 3 (Use \d+ to list them.)
 Partition of: gtest_parent FOR VALUES FROM ('07-01-2016') TO ('08-01-2016')
 
 \d gtest_child2
-                          Table "public.gtest_child2"
+                  Table "generated_stored_tests.gtest_child2"
  Column |  Type  | Collation | Nullable |               Default                
 --------+--------+-----------+----------+--------------------------------------
  f1     | date   |           | not null | 
@@ -885,7 +888,7 @@ Partition of: gtest_parent FOR VALUES FROM ('07-01-2016') TO ('08-01-2016')
 Partition of: gtest_parent FOR VALUES FROM ('08-01-2016') TO ('09-01-2016')
 
 \d gtest_child3
-                          Table "public.gtest_child3"
+                  Table "generated_stored_tests.gtest_child3"
  Column |  Type  | Collation | Nullable |               Default                
 --------+--------+-----------+----------+--------------------------------------
  f1     | date   |           | not null | 
@@ -904,7 +907,7 @@ SELECT tableoid::regclass, * FROM gtest_parent ORDER BY 1, 2, 3;
 -- alter generation expression of parent and all its children altogether
 ALTER TABLE gtest_parent ALTER COLUMN f3 SET EXPRESSION AS (f2 * 2);
 \d gtest_parent
-                   Partitioned table "public.gtest_parent"
+           Partitioned table "generated_stored_tests.gtest_parent"
  Column |  Type  | Collation | Nullable |               Default               
 --------+--------+-----------+----------+-------------------------------------
  f1     | date   |           | not null | 
@@ -914,7 +917,7 @@ Partition key: RANGE (f1)
 Number of partitions: 3 (Use \d+ to list them.)
 
 \d gtest_child
-                          Table "public.gtest_child"
+                  Table "generated_stored_tests.gtest_child"
  Column |  Type  | Collation | Nullable |               Default               
 --------+--------+-----------+----------+-------------------------------------
  f1     | date   |           | not null | 
@@ -923,7 +926,7 @@ Number of partitions: 3 (Use \d+ to list them.)
 Partition of: gtest_parent FOR VALUES FROM ('07-01-2016') TO ('08-01-2016')
 
 \d gtest_child2
-                         Table "public.gtest_child2"
+                 Table "generated_stored_tests.gtest_child2"
  Column |  Type  | Collation | Nullable |               Default               
 --------+--------+-----------+----------+-------------------------------------
  f1     | date   |           | not null | 
@@ -932,7 +935,7 @@ Partition of: gtest_parent FOR VALUES FROM ('07-01-2016') TO ('08-01-2016')
 Partition of: gtest_parent FOR VALUES FROM ('08-01-2016') TO ('09-01-2016')
 
 \d gtest_child3
-                         Table "public.gtest_child3"
+                 Table "generated_stored_tests.gtest_child3"
  Column |  Type  | Collation | Nullable |               Default               
 --------+--------+-----------+----------+-------------------------------------
  f1     | date   |           | not null | 
@@ -989,7 +992,7 @@ SELECT * FROM gtest25 ORDER BY a;
 (2 rows)
 
 \d gtest25
-                                         Table "public.gtest25"
+                                 Table "generated_stored_tests.gtest25"
  Column |       Type       | Collation | Nullable |                       Default                        
 --------+------------------+-----------+----------+------------------------------------------------------
  a      | integer          |           | not null | 
@@ -1013,7 +1016,7 @@ ERROR:  cannot alter type of a column used by a generated column
 DETAIL:  Column "a" is used by generated column "x".
 ALTER TABLE gtest27 ALTER COLUMN x TYPE numeric;
 \d gtest27
-                                Table "public.gtest27"
+                        Table "generated_stored_tests.gtest27"
  Column |  Type   | Collation | Nullable |                  Default                   
 --------+---------+-----------+----------+--------------------------------------------
  a      | integer |           |          | 
@@ -1039,7 +1042,7 @@ ALTER TABLE gtest27
   ALTER COLUMN b TYPE bigint,
   ADD COLUMN x bigint GENERATED ALWAYS AS ((a + b) * 2) STORED;
 \d gtest27
-                              Table "public.gtest27"
+                      Table "generated_stored_tests.gtest27"
  Column |  Type  | Collation | Nullable |                 Default                  
 --------+--------+-----------+----------+------------------------------------------
  a      | bigint |           |          | 
@@ -1053,7 +1056,7 @@ ALTER TABLE gtest27
 ERROR:  cannot alter type of a column used by a generated column
 DETAIL:  Column "a" is used by generated column "x".
 \d gtest27
-                              Table "public.gtest27"
+                      Table "generated_stored_tests.gtest27"
  Column |  Type  | Collation | Nullable |                 Default                  
 --------+--------+-----------+----------+------------------------------------------
  a      | bigint |           |          | 
@@ -1081,7 +1084,7 @@ SELECT * FROM gtest29;
 (2 rows)
 
 \d gtest29
-                            Table "public.gtest29"
+                    Table "generated_stored_tests.gtest29"
  Column |  Type   | Collation | Nullable |              Default               
 --------+---------+-----------+----------+------------------------------------
  a      | integer |           |          | 
@@ -1103,7 +1106,7 @@ SELECT * FROM gtest29;
 (2 rows)
 
 \d gtest29
-                            Table "public.gtest29"
+                    Table "generated_stored_tests.gtest29"
  Column |  Type   | Collation | Nullable |              Default               
 --------+---------+-----------+----------+------------------------------------
  a      | integer |           |          | 
@@ -1122,7 +1125,7 @@ SELECT * FROM gtest29;
 (4 rows)
 
 \d gtest29
-              Table "public.gtest29"
+      Table "generated_stored_tests.gtest29"
  Column |  Type   | Collation | Nullable | Default 
 --------+---------+-----------+----------+---------
  a      | integer |           |          | 
@@ -1131,7 +1134,7 @@ SELECT * FROM gtest29;
 -- check that dependencies between columns have also been removed
 ALTER TABLE gtest29 DROP COLUMN a;  -- should not drop b
 \d gtest29
-              Table "public.gtest29"
+      Table "generated_stored_tests.gtest29"
  Column |  Type   | Collation | Nullable | Default 
 --------+---------+-----------+----------+---------
  b      | integer |           |          | 
@@ -1144,7 +1147,7 @@ CREATE TABLE gtest30 (
 CREATE TABLE gtest30_1 () INHERITS (gtest30);
 ALTER TABLE gtest30 ALTER COLUMN b DROP EXPRESSION;
 \d gtest30
-              Table "public.gtest30"
+      Table "generated_stored_tests.gtest30"
  Column |  Type   | Collation | Nullable | Default 
 --------+---------+-----------+----------+---------
  a      | integer |           |          | 
@@ -1152,7 +1155,7 @@ ALTER TABLE gtest30 ALTER COLUMN b DROP EXPRESSION;
 Number of child tables: 1 (Use \d+ to list them.)
 
 \d gtest30_1
-             Table "public.gtest30_1"
+     Table "generated_stored_tests.gtest30_1"
  Column |  Type   | Collation | Nullable | Default 
 --------+---------+-----------+----------+---------
  a      | integer |           |          | 
@@ -1169,7 +1172,7 @@ CREATE TABLE gtest30_1 () INHERITS (gtest30);
 ALTER TABLE ONLY gtest30 ALTER COLUMN b DROP EXPRESSION;  -- error
 ERROR:  ALTER TABLE / DROP EXPRESSION must be applied to child tables too
 \d gtest30
-                            Table "public.gtest30"
+                    Table "generated_stored_tests.gtest30"
  Column |  Type   | Collation | Nullable |              Default               
 --------+---------+-----------+----------+------------------------------------
  a      | integer |           |          | 
@@ -1177,7 +1180,7 @@ ERROR:  ALTER TABLE / DROP EXPRESSION must be applied to child tables too
 Number of child tables: 1 (Use \d+ to list them.)
 
 \d gtest30_1
-                           Table "public.gtest30_1"
+                   Table "generated_stored_tests.gtest30_1"
  Column |  Type   | Collation | Nullable |              Default               
 --------+---------+-----------+----------+------------------------------------
  a      | integer |           |          | 
@@ -1338,14 +1341,14 @@ CREATE TABLE gtest28a (
 ALTER TABLE gtest28a DROP COLUMN a;
 CREATE TABLE gtest28b (LIKE gtest28a INCLUDING GENERATED);
 \d gtest28*
-                           Table "public.gtest28a"
+                   Table "generated_stored_tests.gtest28a"
  Column |  Type   | Collation | Nullable |              Default               
 --------+---------+-----------+----------+------------------------------------
  b      | integer |           |          | 
  c      | integer |           |          | 
  x      | integer |           |          | generated always as (b * 2) stored
 
-                           Table "public.gtest28b"
+                   Table "generated_stored_tests.gtest28b"
  Column |  Type   | Collation | Nullable |              Default               
 --------+---------+-----------+----------+------------------------------------
  b      | integer |           |          | 
diff --git a/src/test/regress/sql/generated_stored.sql b/src/test/regress/sql/generated_stored.sql
index cb55d77821f..c18e0e1f655 100644
--- a/src/test/regress/sql/generated_stored.sql
+++ b/src/test/regress/sql/generated_stored.sql
@@ -2,12 +2,16 @@
 SELECT attrelid, attname, attgenerated FROM pg_attribute WHERE attgenerated NOT IN ('', 's');
 
 
+CREATE SCHEMA generated_stored_tests;
+GRANT USAGE ON SCHEMA generated_stored_tests TO PUBLIC;
+SET search_path = generated_stored_tests;
+
 CREATE TABLE gtest0 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (55) STORED);
 CREATE TABLE gtest1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED);
 
-SELECT table_name, column_name, column_default, is_nullable, is_generated, generation_expression FROM information_schema.columns WHERE table_name LIKE 'gtest_' ORDER BY 1, 2;
+SELECT table_name, column_name, column_default, is_nullable, is_generated, generation_expression FROM information_schema.columns WHERE table_schema = 'generated_stored_tests' ORDER BY 1, 2;
 
-SELECT table_name, column_name, dependent_column FROM information_schema.column_column_usage ORDER BY 1, 2, 3;
+SELECT table_name, column_name, dependent_column FROM information_schema.column_column_usage WHERE table_schema = 'generated_stored_tests' ORDER BY 1, 2, 3;
 
 \d gtest1
 
-- 
2.44.0



  [text/plain] v0-0003-Remove-useless-initializations.patch (996B, ../../[email protected]/4-v0-0003-Remove-useless-initializations.patch)
  download | inline diff:
From 037ca235379e7d1ca47af3b3f980cb21d22ab061 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <[email protected]>
Date: Mon, 29 Apr 2024 09:46:43 +0200
Subject: [PATCH v0 3/5] Remove useless initializations

The struct is already initialized to all zeros right before this, and
randomly initializing a few but not all fields to zero again has no
technical or educational value.
---
 src/backend/utils/cache/relcache.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index 262c9878dd3..05c4ae79707 100644
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -535,8 +535,6 @@ RelationBuildTupleDesc(Relation relation)
 
 	constr = (TupleConstr *) MemoryContextAllocZero(CacheMemoryContext,
 													sizeof(TupleConstr));
-	constr->has_not_null = false;
-	constr->has_generated_stored = false;
 
 	/*
 	 * Form a scan key that selects only user attributes (attnum > 0).
-- 
2.44.0



  [text/plain] v0-0004-Remove-useless-code.patch (2.5K, ../../[email protected]/5-v0-0004-Remove-useless-code.patch)
  download | inline diff:
From 35d42f2fea33254b9c860ed54b5647728dd508ba Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <[email protected]>
Date: Mon, 29 Apr 2024 09:46:44 +0200
Subject: [PATCH v0 4/5] Remove useless code

BuildDescForRelation() goes out of its way to fill in
->constr->has_not_null, but that value is not used for anything later,
so this code can all be removed.  Note that BuildDescForRelation()
doesn't make any effort to fill in the rest of ->constr, so there is
no claim that that structure is completely filled in.
---
 src/backend/commands/tablecmds.c | 25 +++----------------------
 1 file changed, 3 insertions(+), 22 deletions(-)

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index f1725c9da8c..4ec600e21d1 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -1302,7 +1302,9 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId,
  *
  * Given a list of ColumnDef nodes, build a TupleDesc.
  *
- * Note: tdtypeid will need to be filled in later on.
+ * Note: This is only for the limited purpose of table and view creation.  Not
+ * everything is filled in.  A real tuple descriptor should be obtained from
+ * the relcache.
  */
 TupleDesc
 BuildDescForRelation(const List *columns)
@@ -1311,7 +1313,6 @@ BuildDescForRelation(const List *columns)
 	AttrNumber	attnum;
 	ListCell   *l;
 	TupleDesc	desc;
-	bool		has_not_null;
 	char	   *attname;
 	Oid			atttypid;
 	int32		atttypmod;
@@ -1323,7 +1324,6 @@ BuildDescForRelation(const List *columns)
 	 */
 	natts = list_length(columns);
 	desc = CreateTemplateTupleDesc(natts);
-	has_not_null = false;
 
 	attnum = 0;
 
@@ -1369,7 +1369,6 @@ BuildDescForRelation(const List *columns)
 
 		/* Fill in additional stuff not handled by TupleDescInitEntry */
 		att->attnotnull = entry->is_not_null;
-		has_not_null |= entry->is_not_null;
 		att->attislocal = entry->is_local;
 		att->attinhcount = entry->inhcount;
 		att->attidentity = entry->identity;
@@ -1381,24 +1380,6 @@ BuildDescForRelation(const List *columns)
 			att->attstorage = GetAttributeStorage(att->atttypid, entry->storage_name);
 	}
 
-	if (has_not_null)
-	{
-		TupleConstr *constr = (TupleConstr *) palloc0(sizeof(TupleConstr));
-
-		constr->has_not_null = true;
-		constr->has_generated_stored = false;
-		constr->defval = NULL;
-		constr->missing = NULL;
-		constr->num_defval = 0;
-		constr->check = NULL;
-		constr->num_check = 0;
-		desc->constr = constr;
-	}
-	else
-	{
-		desc->constr = NULL;
-	}
-
 	return desc;
 }
 
-- 
2.44.0



  [text/plain] v0-0005-WIP-Virtual-generated-columns.patch (159.7K, ../../[email protected]/6-v0-0005-WIP-Virtual-generated-columns.patch)
  download | inline diff:
From 6960ee6add5801b9672db5dc94775f03b01ab91e Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <[email protected]>
Date: Mon, 29 Apr 2024 09:46:44 +0200
Subject: [PATCH v0 5/5] WIP: Virtual generated columns

This adds a new variant of generated columns that are computed on read
(like a view, unlike the existing stored generated columns, which are
computed on write, like a materialized view).
---
 contrib/pageinspect/expected/page.out         |  35 +
 contrib/pageinspect/sql/page.sql              |  17 +
 .../postgres_fdw/expected/postgres_fdw.out    |  81 +-
 contrib/postgres_fdw/sql/postgres_fdw.sql     |   9 +-
 doc/src/sgml/catalogs.sgml                    |   4 +-
 doc/src/sgml/ddl.sgml                         |   9 +-
 doc/src/sgml/ref/create_foreign_table.sgml    |  11 +-
 doc/src/sgml/ref/create_table.sgml            |  22 +-
 doc/src/sgml/ref/create_trigger.sgml          |   2 +-
 doc/src/sgml/trigger.sgml                     |   2 +
 src/backend/access/common/tupdesc.c           |   3 +
 src/backend/commands/indexcmds.c              |  29 +-
 src/backend/commands/tablecmds.c              |  39 +-
 src/backend/commands/trigger.c                |  48 +-
 src/backend/executor/execMain.c               |   5 +
 src/backend/parser/analyze.c                  |   8 +
 src/backend/parser/gram.y                     |  15 +-
 src/backend/parser/parse_clause.c             |   4 +
 src/backend/parser/parse_relation.c           |   9 +-
 src/backend/parser/parse_utilcmd.c            |  27 +-
 src/backend/rewrite/rewriteHandler.c          | 164 +++-
 src/backend/utils/cache/partcache.c           |   3 +
 src/backend/utils/cache/relcache.c            |   2 +
 src/bin/pg_dump/pg_dump.c                     |   3 +
 src/bin/pg_dump/t/002_pg_dump.pl              |   6 +-
 src/bin/psql/describe.c                       |   6 +
 src/include/access/tupdesc.h                  |   1 +
 src/include/catalog/pg_attribute.h            |   1 +
 src/include/nodes/parsenodes.h                |   3 +
 src/include/parser/kwlist.h                   |   1 +
 src/include/parser/parse_node.h               |   1 +
 src/include/rewrite/rewriteHandler.h          |   2 +
 src/pl/plperl/expected/plperl_trigger.out     |   7 +-
 src/pl/plperl/plperl.c                        |   3 +
 src/pl/plperl/sql/plperl_trigger.sql          |   3 +-
 src/pl/plpython/expected/plpython_trigger.out |   7 +-
 src/pl/plpython/plpy_typeio.c                 |   3 +
 src/pl/plpython/sql/plpython_trigger.sql      |   3 +-
 src/pl/tcl/expected/pltcl_trigger.out         |  19 +-
 src/pl/tcl/pltcl.c                            |   3 +
 src/pl/tcl/sql/pltcl_trigger.sql              |   3 +-
 .../regress/expected/create_table_like.out    |  23 +-
 .../regress/expected/generated_stored.out     |   2 +-
 ...rated_stored.out => generated_virtual.out} | 745 ++++++++----------
 src/test/regress/parallel_schedule            |   3 +
 src/test/regress/sql/create_table_like.sql    |   2 +-
 src/test/regress/sql/generated_stored.sql     |   2 +-
 ...rated_stored.sql => generated_virtual.sql} | 265 ++++---
 src/test/subscription/t/011_generated.pl      |  38 +-
 49 files changed, 1027 insertions(+), 676 deletions(-)
 copy src/test/regress/expected/{generated_stored.out => generated_virtual.out} (71%)
 copy src/test/regress/sql/{generated_stored.sql => generated_virtual.sql} (76%)

diff --git a/contrib/pageinspect/expected/page.out b/contrib/pageinspect/expected/page.out
index 80ddb45a60a..7e0b09e279b 100644
--- a/contrib/pageinspect/expected/page.out
+++ b/contrib/pageinspect/expected/page.out
@@ -208,6 +208,41 @@ select tuple_data_split('test8'::regclass, t_data, t_infomask, t_infomask2, t_bi
 (1 row)
 
 drop table test8;
+-- check storage of generated columns
+-- stored
+create table test9s (a int not null, b int generated always as (a * 2) stored);
+insert into test9s values (131584);
+select t_infomask, t_bits, t_data from heap_page_items(get_raw_page('test9s', 0));
+ t_infomask | t_bits |       t_data       
+------------+--------+--------------------
+       2048 |        | \x0002020000040400
+(1 row)
+
+select tuple_data_split('test9s'::regclass, t_data, t_infomask, t_infomask2, t_bits)
+    from heap_page_items(get_raw_page('test9s', 0));
+       tuple_data_split        
+-------------------------------
+ {"\\x00020200","\\x00040400"}
+(1 row)
+
+drop table test9s;
+-- virtual
+create table test9v (a int not null, b int generated always as (a * 2) virtual);
+insert into test9v values (131584);
+select t_infomask, t_bits, t_data from heap_page_items(get_raw_page('test9v', 0));
+ t_infomask |  t_bits  |   t_data   
+------------+----------+------------
+       2049 | 10000000 | \x00020200
+(1 row)
+
+select tuple_data_split('test9v'::regclass, t_data, t_infomask, t_infomask2, t_bits)
+    from heap_page_items(get_raw_page('test9v', 0));
+   tuple_data_split   
+----------------------
+ {"\\x00020200",NULL}
+(1 row)
+
+drop table test9v;
 -- Failure with incorrect page size
 -- Suppress the DETAIL message, to allow the tests to work across various
 -- page sizes.
diff --git a/contrib/pageinspect/sql/page.sql b/contrib/pageinspect/sql/page.sql
index 5bff568d3b5..186dda1e8d0 100644
--- a/contrib/pageinspect/sql/page.sql
+++ b/contrib/pageinspect/sql/page.sql
@@ -84,6 +84,23 @@ CREATE TEMP TABLE test1 (a int, b int);
     from heap_page_items(get_raw_page('test8', 0));
 drop table test8;
 
+-- check storage of generated columns
+-- stored
+create table test9s (a int not null, b int generated always as (a * 2) stored);
+insert into test9s values (131584);
+select t_infomask, t_bits, t_data from heap_page_items(get_raw_page('test9s', 0));
+select tuple_data_split('test9s'::regclass, t_data, t_infomask, t_infomask2, t_bits)
+    from heap_page_items(get_raw_page('test9s', 0));
+drop table test9s;
+
+-- virtual
+create table test9v (a int not null, b int generated always as (a * 2) virtual);
+insert into test9v values (131584);
+select t_infomask, t_bits, t_data from heap_page_items(get_raw_page('test9v', 0));
+select tuple_data_split('test9v'::regclass, t_data, t_infomask, t_infomask2, t_bits)
+    from heap_page_items(get_raw_page('test9v', 0));
+drop table test9v;
+
 -- Failure with incorrect page size
 -- Suppress the DETAIL message, to allow the tests to work across various
 -- page sizes.
diff --git a/contrib/postgres_fdw/expected/postgres_fdw.out b/contrib/postgres_fdw/expected/postgres_fdw.out
index 078b8a966f8..7a3e71c07b4 100644
--- a/contrib/postgres_fdw/expected/postgres_fdw.out
+++ b/contrib/postgres_fdw/expected/postgres_fdw.out
@@ -7215,65 +7215,68 @@ select * from rem1;
 -- ===================================================================
 create table gloc1 (
   a int,
-  b int generated always as (a * 2) stored);
+  b int generated always as (a * 2) stored,
+  c int
+);
 alter table gloc1 set (autovacuum_enabled = 'false');
 create foreign table grem1 (
   a int,
-  b int generated always as (a * 2) stored)
-  server loopback options(table_name 'gloc1');
+  b int generated always as (a * 2) stored,
+  c int generated always as (a * 3) virtual
+) server loopback options(table_name 'gloc1');
 explain (verbose, costs off)
 insert into grem1 (a) values (1), (2);
-                            QUERY PLAN                             
--------------------------------------------------------------------
+                                  QUERY PLAN                                   
+-------------------------------------------------------------------------------
  Insert on public.grem1
-   Remote SQL: INSERT INTO public.gloc1(a, b) VALUES ($1, DEFAULT)
+   Remote SQL: INSERT INTO public.gloc1(a, b, c) VALUES ($1, DEFAULT, DEFAULT)
    Batch Size: 1
    ->  Values Scan on "*VALUES*"
-         Output: "*VALUES*".column1, NULL::integer
+         Output: "*VALUES*".column1, NULL::integer, NULL::integer
 (5 rows)
 
 insert into grem1 (a) values (1), (2);
 explain (verbose, costs off)
 update grem1 set a = 22 where a = 2;
-                                     QUERY PLAN                                     
-------------------------------------------------------------------------------------
+                                       QUERY PLAN                                       
+----------------------------------------------------------------------------------------
  Update on public.grem1
-   Remote SQL: UPDATE public.gloc1 SET a = $2, b = DEFAULT WHERE ctid = $1
+   Remote SQL: UPDATE public.gloc1 SET a = $2, b = DEFAULT, c = DEFAULT WHERE ctid = $1
    ->  Foreign Scan on public.grem1
          Output: 22, ctid, grem1.*
-         Remote SQL: SELECT a, b, ctid FROM public.gloc1 WHERE ((a = 2)) FOR UPDATE
+         Remote SQL: SELECT a, b, c, ctid FROM public.gloc1 WHERE ((a = 2)) FOR UPDATE
 (5 rows)
 
 update grem1 set a = 22 where a = 2;
 select * from gloc1;
- a  | b  
-----+----
-  1 |  2
- 22 | 44
+ a  | b  | c 
+----+----+---
+  1 |  2 |  
+ 22 | 44 |  
 (2 rows)
 
 select * from grem1;
- a  | b  
-----+----
-  1 |  2
- 22 | 44
+ a  | b  | c  
+----+----+----
+  1 |  2 |  3
+ 22 | 44 | 66
 (2 rows)
 
 delete from grem1;
 -- test copy from
 copy grem1 from stdin;
 select * from gloc1;
- a | b 
----+---
- 1 | 2
- 2 | 4
+ a | b | c 
+---+---+---
+ 1 | 2 |  
+ 2 | 4 |  
 (2 rows)
 
 select * from grem1;
- a | b 
----+---
- 1 | 2
- 2 | 4
+ a | b | c 
+---+---+---
+ 1 | 2 | 3
+ 2 | 4 | 6
 (2 rows)
 
 delete from grem1;
@@ -7281,28 +7284,28 @@ delete from grem1;
 alter server loopback options (add batch_size '10');
 explain (verbose, costs off)
 insert into grem1 (a) values (1), (2);
-                            QUERY PLAN                             
--------------------------------------------------------------------
+                                  QUERY PLAN                                   
+-------------------------------------------------------------------------------
  Insert on public.grem1
-   Remote SQL: INSERT INTO public.gloc1(a, b) VALUES ($1, DEFAULT)
+   Remote SQL: INSERT INTO public.gloc1(a, b, c) VALUES ($1, DEFAULT, DEFAULT)
    Batch Size: 10
    ->  Values Scan on "*VALUES*"
-         Output: "*VALUES*".column1, NULL::integer
+         Output: "*VALUES*".column1, NULL::integer, NULL::integer
 (5 rows)
 
 insert into grem1 (a) values (1), (2);
 select * from gloc1;
- a | b 
----+---
- 1 | 2
- 2 | 4
+ a | b | c 
+---+---+---
+ 1 | 2 |  
+ 2 | 4 |  
 (2 rows)
 
 select * from grem1;
- a | b 
----+---
- 1 | 2
- 2 | 4
+ a | b | c 
+---+---+---
+ 1 | 2 | 3
+ 2 | 4 | 6
 (2 rows)
 
 delete from grem1;
diff --git a/contrib/postgres_fdw/sql/postgres_fdw.sql b/contrib/postgres_fdw/sql/postgres_fdw.sql
index 09ba234e43d..1fc28b3e264 100644
--- a/contrib/postgres_fdw/sql/postgres_fdw.sql
+++ b/contrib/postgres_fdw/sql/postgres_fdw.sql
@@ -1806,12 +1806,15 @@ CREATE VIEW rw_view AS SELECT * FROM parent_tbl WHERE a < 5 WITH CHECK OPTION;
 -- ===================================================================
 create table gloc1 (
   a int,
-  b int generated always as (a * 2) stored);
+  b int generated always as (a * 2) stored,
+  c int
+);
 alter table gloc1 set (autovacuum_enabled = 'false');
 create foreign table grem1 (
   a int,
-  b int generated always as (a * 2) stored)
-  server loopback options(table_name 'gloc1');
+  b int generated always as (a * 2) stored,
+  c int generated always as (a * 3) virtual
+) server loopback options(table_name 'gloc1');
 explain (verbose, costs off)
 insert into grem1 (a) values (1), (2);
 insert into grem1 (a) values (1), (2);
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 2907079e2a6..2b93c05be42 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -1318,8 +1318,8 @@ <title><structname>pg_attribute</structname> Columns</title>
       </para>
       <para>
        If a zero byte (<literal>''</literal>), then not a generated column.
-       Otherwise, <literal>s</literal> = stored.  (Other values might be added
-       in the future.)
+       Otherwise, <literal>s</literal> = stored, <literal>v</literal> =
+       virtual.
       </para></entry>
      </row>
 
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 026bfff70f3..4449d70f235 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -361,7 +361,6 @@ <title>Generated Columns</title>
    storage and is computed when it is read.  Thus, a virtual generated column
    is similar to a view and a stored generated column is similar to a
    materialized view (except that it is always updated automatically).
-   <productname>PostgreSQL</productname> currently implements only stored generated columns.
   </para>
 
   <para>
@@ -371,12 +370,12 @@ <title>Generated Columns</title>
 CREATE TABLE people (
     ...,
     height_cm numeric,
-    height_in numeric <emphasis>GENERATED ALWAYS AS (height_cm / 2.54) STORED</emphasis>
+    height_in numeric <emphasis>GENERATED ALWAYS AS (height_cm / 2.54)</emphasis>
 );
 </programlisting>
-   The keyword <literal>STORED</literal> must be specified to choose the
-   stored kind of generated column.  See <xref linkend="sql-createtable"/> for
-   more details.
+   A generated column is by default of the virtual kind.  Use the keywords
+   <literal>VIRTUAL</literal> or <literal>STORED</literal> to make the choice
+   explicit.  See <xref linkend="sql-createtable"/> for more details.
   </para>
 
   <para>
diff --git a/doc/src/sgml/ref/create_foreign_table.sgml b/doc/src/sgml/ref/create_foreign_table.sgml
index dc4b9075990..21b5d6a14d0 100644
--- a/doc/src/sgml/ref/create_foreign_table.sgml
+++ b/doc/src/sgml/ref/create_foreign_table.sgml
@@ -47,7 +47,7 @@
   NULL |
   CHECK ( <replaceable class="parameter">expression</replaceable> ) [ NO INHERIT ] |
   DEFAULT <replaceable>default_expr</replaceable> |
-  GENERATED ALWAYS AS ( <replaceable>generation_expr</replaceable> ) STORED }
+  GENERATED ALWAYS AS ( <replaceable>generation_expr</replaceable> ) [ STORED | VIRTUAL ] }
 
 <phrase>and <replaceable class="parameter">table_constraint</replaceable> is:</phrase>
 
@@ -275,7 +275,7 @@ <title>Parameters</title>
    </varlistentry>
 
    <varlistentry>
-    <term><literal>GENERATED ALWAYS AS ( <replaceable>generation_expr</replaceable> ) STORED</literal><indexterm><primary>generated column</primary></indexterm></term>
+    <term><literal>GENERATED ALWAYS AS ( <replaceable>generation_expr</replaceable> ) [ STORED | VIRTUAL ]</literal><indexterm><primary>generated column</primary></indexterm></term>
     <listitem>
      <para>
       This clause creates the column as a <firstterm>generated
@@ -284,10 +284,13 @@ <title>Parameters</title>
      </para>
 
      <para>
-      The keyword <literal>STORED</literal> is required to signify that the
+      When <literal>VIRTUAL</literal> is specified, the column will be
+      computed when it is read.  (The foreign-data wrapper will see it as a
+      null value in new rows and may choose to store it as a null value or
+      ignore it altogether.)  When <literal>STORED</literal> is specified, the
       column will be computed on write.  (The computed value will be presented
       to the foreign-data wrapper for storage and must be returned on
-      reading.)
+      reading.)  <literal>VIRTUAL</literal> is the default.
      </para>
 
      <para>
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 02f31d2d6fd..a69b41f4973 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -65,7 +65,7 @@
   NULL |
   CHECK ( <replaceable class="parameter">expression</replaceable> ) [ NO INHERIT ] |
   DEFAULT <replaceable>default_expr</replaceable> |
-  GENERATED ALWAYS AS ( <replaceable>generation_expr</replaceable> ) STORED |
+  GENERATED ALWAYS AS ( <replaceable>generation_expr</replaceable> ) [ STORED | VIRTUAL ] |
   GENERATED { ALWAYS | BY DEFAULT } AS IDENTITY [ ( <replaceable>sequence_options</replaceable> ) ] |
   UNIQUE [ NULLS [ NOT ] DISTINCT ] <replaceable class="parameter">index_parameters</replaceable> |
   PRIMARY KEY <replaceable class="parameter">index_parameters</replaceable> |
@@ -721,8 +721,9 @@ <title>Parameters</title>
         <term><literal>INCLUDING GENERATED</literal></term>
         <listitem>
          <para>
-          Any generation expressions of copied column definitions will be
-          copied.  By default, new columns will be regular base columns.
+          Any generation expressions as well as the stored/virtual choice of
+          copied column definitions will be copied.  By default, new columns
+          will be regular base columns.
          </para>
         </listitem>
        </varlistentry>
@@ -898,7 +899,7 @@ <title>Parameters</title>
    </varlistentry>
 
    <varlistentry id="sql-createtable-parms-generated-stored">
-    <term><literal>GENERATED ALWAYS AS ( <replaceable>generation_expr</replaceable> ) STORED</literal><indexterm><primary>generated column</primary></indexterm></term>
+    <term><literal>GENERATED ALWAYS AS ( <replaceable>generation_expr</replaceable> ) [ STORED | VIRTUAL ]</literal><indexterm><primary>generated column</primary></indexterm></term>
     <listitem>
      <para>
       This clause creates the column as a <firstterm>generated
@@ -907,8 +908,11 @@ <title>Parameters</title>
      </para>
 
      <para>
-      The keyword <literal>STORED</literal> is required to signify that the
-      column will be computed on write and will be stored on disk.
+      When <literal>VIRTUAL</literal> is specified, the column will be
+      computed when it is read, and it will not occupy any storage.  When
+      <literal>STORED</literal> is specified, the column will be computed on
+      write and will be stored on disk.  <literal>VIRTUAL</literal> is the
+      default.
      </para>
 
      <para>
@@ -2436,9 +2440,9 @@ <title>Multiple Identity Columns</title>
    <title>Generated Columns</title>
 
    <para>
-    The option <literal>STORED</literal> is not standard but is also used by
-    other SQL implementations.  The SQL standard does not specify the storage
-    of generated columns.
+    The options <literal>STORED</literal> and <literal>VIRTUAL</literal> are
+    not standard but are also used by other SQL implementations.  The SQL
+    standard does not specify the storage of generated columns.
    </para>
   </refsect2>
 
diff --git a/doc/src/sgml/ref/create_trigger.sgml b/doc/src/sgml/ref/create_trigger.sgml
index 982ab6f3ee4..752fe50860a 100644
--- a/doc/src/sgml/ref/create_trigger.sgml
+++ b/doc/src/sgml/ref/create_trigger.sgml
@@ -279,7 +279,7 @@ <title>Parameters</title>
      <para>
       <literal>INSTEAD OF UPDATE</literal> events do not allow a list of columns.
       A column list cannot be specified when requesting transition relations,
-      either.
+      either.  Virtual generated columns are not supported in the column list.
      </para>
     </listitem>
    </varlistentry>
diff --git a/doc/src/sgml/trigger.sgml b/doc/src/sgml/trigger.sgml
index a5390ff6443..a758fda914f 100644
--- a/doc/src/sgml/trigger.sgml
+++ b/doc/src/sgml/trigger.sgml
@@ -289,6 +289,8 @@ <title>Overview of Trigger Behavior</title>
     <literal>BEFORE</literal> trigger.  Changes to the value of a generated
     column in a <literal>BEFORE</literal> trigger are ignored and will be
     overwritten.
+    Virtual generated columns are never computed when triggers fire; they will
+    always appear as null inside a trigger function.
    </para>
 
    <para>
diff --git a/src/backend/access/common/tupdesc.c b/src/backend/access/common/tupdesc.c
index 47379fef220..13840ba533c 100644
--- a/src/backend/access/common/tupdesc.c
+++ b/src/backend/access/common/tupdesc.c
@@ -190,6 +190,7 @@ CreateTupleDescCopyConstr(TupleDesc tupdesc)
 
 		cpy->has_not_null = constr->has_not_null;
 		cpy->has_generated_stored = constr->has_generated_stored;
+		cpy->has_generated_virtual = constr->has_generated_virtual;
 
 		if ((cpy->num_defval = constr->num_defval) > 0)
 		{
@@ -494,6 +495,8 @@ equalTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2)
 			return false;
 		if (constr1->has_generated_stored != constr2->has_generated_stored)
 			return false;
+		if (constr1->has_generated_virtual != constr2->has_generated_virtual)
+			return false;
 		n = constr1->num_defval;
 		if (n != (int) constr2->num_defval)
 			return false;
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index d9016ef487b..dd9d042cad4 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -1097,6 +1097,9 @@ DefineIndex(Oid tableId,
 	/*
 	 * We disallow indexes on system columns.  They would not necessarily get
 	 * updated correctly, and they don't seem useful anyway.
+	 *
+	 * Also disallow virtual generated columns in indexes (use expression
+	 * index instead).
 	 */
 	for (int i = 0; i < indexInfo->ii_NumIndexAttrs; i++)
 	{
@@ -1106,14 +1109,22 @@ DefineIndex(Oid tableId,
 			ereport(ERROR,
 					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 					 errmsg("index creation on system columns is not supported")));
+
+
+		if (TupleDescAttr(RelationGetDescr(rel), attno - 1)->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("index creation on virtual generated columns is not supported")));
 	}
 
 	/*
-	 * Also check for system columns used in expressions or predicates.
+	 * Also check for system and generated columns used in expressions or
+	 * predicates.
 	 */
 	if (indexInfo->ii_Expressions || indexInfo->ii_Predicate)
 	{
 		Bitmapset  *indexattrs = NULL;
+		int			j;
 
 		pull_varattnos((Node *) indexInfo->ii_Expressions, 1, &indexattrs);
 		pull_varattnos((Node *) indexInfo->ii_Predicate, 1, &indexattrs);
@@ -1126,6 +1137,22 @@ DefineIndex(Oid tableId,
 						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 						 errmsg("index creation on system columns is not supported")));
 		}
+
+		/*
+		 * XXX Virtual generated columns in index expressions or predicates
+		 * could be supported, but it needs support in
+		 * RelationGetIndexExpressions() and RelationGetIndexPredicate().
+		 */
+		j = -1;
+		while ((j = bms_next_member(indexattrs, j)) >= 0)
+		{
+			AttrNumber	attno = j + FirstLowInvalidHeapAttributeNumber;
+
+			if (TupleDescAttr(RelationGetDescr(rel), attno - 1)->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("index creation on virtual generated columns is not supported")));
+		}
 	}
 
 	/* Is index safe for others to ignore?  See set_indexsafe_procflags() */
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 4ec600e21d1..b597a4ee80a 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -6093,7 +6093,7 @@ ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap, LOCKMODE lockmode)
 		{
 			case CONSTR_CHECK:
 				needscan = true;
-				con->qualstate = ExecPrepareExpr((Expr *) con->qual, estate);
+				con->qualstate = ExecPrepareExpr((Expr *) expand_generated_columns_in_expr(con->qual, newrel ? newrel : oldrel), estate);
 				break;
 			case CONSTR_FOREIGN:
 				/* Nothing to do here */
@@ -7590,6 +7590,8 @@ ATExecDropNotNull(Relation rel, const char *colName, bool recurse,
 				 errmsg("cannot alter system column \"%s\"",
 						colName)));
 
+	// FIXME: virtual generated columns
+
 	if (attTup->attidentity)
 		ereport(ERROR,
 				(errcode(ERRCODE_SYNTAX_ERROR),
@@ -7849,6 +7851,8 @@ ATExecSetNotNull(List **wqueue, Relation rel, char *conName, char *colName,
 				 errmsg("cannot alter system column \"%s\"",
 						colName)));
 
+	// FIXME: virtual generated columns
+
 	/* See if there's already a constraint */
 	constr_rel = table_open(ConstraintRelationId, RowExclusiveLock);
 	ScanKeyInit(&skey,
@@ -8545,6 +8549,7 @@ ATExecSetExpression(AlteredTableInfo *tab, Relation rel, const char *colName,
 				 errmsg("cannot alter system column \"%s\"",
 						colName)));
 
+	// FIXME
 	if (attTup->attgenerated != ATTRIBUTE_GENERATED_STORED)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
@@ -10064,6 +10069,19 @@ ATAddForeignKeyConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
 						 errmsg("invalid %s action for foreign key constraint containing generated column",
 								"ON DELETE")));
 		}
+
+		/*
+		 * FKs on virtual columns are not supported.  This would require
+		 * various additional support in ri_triggers.c, including special
+		 * handling in ri_NullCheck(), ri_KeysEqual(),
+		 * RI_FKey_fk_upd_check_required() (since all virtual columns appear
+		 * as NULL there).  Also not really practical as long as you can't
+		 * index virtual columns.
+		 */
+		if (attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("foreign key constraints on virtual generated columns are not supported")));
 	}
 
 	/*
@@ -12119,7 +12137,7 @@ ATExecValidateConstraint(List **wqueue, Relation rel, char *constrName,
 			val = SysCacheGetAttrNotNull(CONSTROID, tuple,
 										 Anum_pg_constraint_conbin);
 			conbin = TextDatumGetCString(val);
-			newcon->qual = (Node *) stringToNode(conbin);
+			newcon->qual = (Node *) expand_generated_columns_in_expr(stringToNode(conbin), rel);
 
 			/* Find or create work queue entry for this table */
 			tab = ATGetQueueEntry(wqueue, rel);
@@ -13438,6 +13456,7 @@ ATPrepAlterColumnType(List **wqueue,
 					   list_make1_oid(rel->rd_rel->reltype),
 					   0);
 
+	// FIXME
 	if (tab->relkind == RELKIND_RELATION ||
 		tab->relkind == RELKIND_PARTITIONED_TABLE)
 	{
@@ -18748,8 +18767,11 @@ ComputePartitionAttrs(ParseState *pstate, Relation rel, List *partParams, AttrNu
 						 parser_errposition(pstate, pelem->location)));
 
 			/*
-			 * Generated columns cannot work: They are computed after BEFORE
-			 * triggers, but partition routing is done before all triggers.
+			 * Stored generated columns cannot work: They are computed after
+			 * BEFORE triggers, but partition routing is done before all
+			 * triggers.  Maybe virtual generated columns could be made to
+			 * work, but then they would need to be handled as an expression
+			 * below.
 			 */
 			if (attform->attgenerated)
 				ereport(ERROR,
@@ -18831,9 +18853,12 @@ ComputePartitionAttrs(ParseState *pstate, Relation rel, List *partParams, AttrNu
 				}
 
 				/*
-				 * Generated columns cannot work: They are computed after
-				 * BEFORE triggers, but partition routing is done before all
-				 * triggers.
+				 * Stored generated columns cannot work: They are computed
+				 * after BEFORE triggers, but partition routing is done before
+				 * all triggers.  Virtual generated columns could probably
+				 * work, but it would require more work elsewhere (for example
+				 * SET EXPRESSION would need to check whether the column is
+				 * used in partition keys).  Seems safer to prohibit for now.
 				 */
 				i = -1;
 				while ((i = bms_next_member(expr_attrs, i)) >= 0)
diff --git a/src/backend/commands/trigger.c b/src/backend/commands/trigger.c
index 35eb7180f7e..e26dbadea40 100644
--- a/src/backend/commands/trigger.c
+++ b/src/backend/commands/trigger.c
@@ -43,6 +43,7 @@
 #include "parser/parse_relation.h"
 #include "partitioning/partdesc.h"
 #include "pgstat.h"
+#include "rewrite/rewriteHandler.h"
 #include "rewrite/rewriteManip.h"
 #include "storage/lmgr.h"
 #include "utils/acl.h"
@@ -101,6 +102,7 @@ static void AfterTriggerSaveEvent(EState *estate, ResultRelInfo *relinfo,
 								  bool is_crosspart_update);
 static void AfterTriggerEnlargeQueryState(void);
 static bool before_stmt_triggers_fired(Oid relid, CmdType cmdType);
+static void check_modified_virtual_generated(TupleDesc tupdesc, HeapTuple tuple);
 
 
 /*
@@ -641,7 +643,8 @@ CreateTriggerFiringOn(CreateTrigStmt *stmt, const char *queryString,
 					if (TRIGGER_FOR_BEFORE(tgtype) &&
 						var->varattno == 0 &&
 						RelationGetDescr(rel)->constr &&
-						RelationGetDescr(rel)->constr->has_generated_stored)
+						(RelationGetDescr(rel)->constr->has_generated_stored ||
+						 RelationGetDescr(rel)->constr->has_generated_virtual))
 						ereport(ERROR,
 								(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
 								 errmsg("BEFORE trigger's WHEN condition cannot reference NEW generated columns"),
@@ -943,6 +946,13 @@ CreateTriggerFiringOn(CreateTrigStmt *stmt, const char *queryString,
 						 errmsg("column \"%s\" of relation \"%s\" does not exist",
 								name, RelationGetRelationName(rel))));
 
+			/* Currently doesn't work. */
+			if (TupleDescAttr(RelationGetDescr(rel), attnum - 1)->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
+				ereport(ERROR,
+						errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						errmsg("virtual generated columns are not supported as trigger columns"),
+						errdetail("Column \"%s\" is a virtual generated column.", name));
+
 			/* Check for duplicates */
 			for (j = i - 1; j >= 0; j--)
 			{
@@ -2502,6 +2512,8 @@ ExecBRInsertTriggers(EState *estate, ResultRelInfo *relinfo,
 		}
 		else if (newtuple != oldtuple)
 		{
+			check_modified_virtual_generated(RelationGetDescr(relinfo->ri_RelationDesc), newtuple);
+
 			ExecForceStoreHeapTuple(newtuple, slot, false);
 
 			/*
@@ -3059,6 +3071,8 @@ ExecBRUpdateTriggers(EState *estate, EPQState *epqstate,
 		}
 		else if (newtuple != oldtuple)
 		{
+			check_modified_virtual_generated(RelationGetDescr(relinfo->ri_RelationDesc), newtuple);
+
 			ExecForceStoreHeapTuple(newtuple, newslot, false);
 
 			/*
@@ -3489,6 +3503,7 @@ TriggerEnabled(EState *estate, ResultRelInfo *relinfo,
 
 			oldContext = MemoryContextSwitchTo(estate->es_query_cxt);
 			tgqual = stringToNode(trigger->tgqual);
+			tgqual = (Node *) expand_generated_columns_in_expr(tgqual, relinfo->ri_RelationDesc);
 			/* Change references to OLD and NEW to INNER_VAR and OUTER_VAR */
 			ChangeVarNodes(tgqual, PRS2_OLD_VARNO, INNER_VAR, 0);
 			ChangeVarNodes(tgqual, PRS2_NEW_VARNO, OUTER_VAR, 0);
@@ -6594,3 +6609,34 @@ pg_trigger_depth(PG_FUNCTION_ARGS)
 {
 	PG_RETURN_INT32(MyTriggerDepth);
 }
+
+/*
+ * Check whether a trigger modified a virtual generated column and error if
+ * so.
+ *
+ * We need to check this so that we don't end up storing a non-null value in a
+ * virtual generated column.
+ *
+ * We don't need to check for stored generated columns, since those will be
+ * overwritten later anyway.
+ */
+static void
+check_modified_virtual_generated(TupleDesc tupdesc, HeapTuple tuple)
+{
+	if (!(tupdesc->constr && tupdesc->constr->has_generated_virtual))
+		return;
+
+	for (int i = 0; i < tupdesc->natts; i++)
+	{
+		if (TupleDescAttr(tupdesc, i)->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
+		{
+			bool		isnull;
+
+			fastgetattr(tuple, i + 1, tupdesc, &isnull);
+			if (!isnull)
+				ereport(ERROR,
+						(errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
+						 errmsg("trigger modified virtual generated column value")));
+		}
+	}
+}
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index 4d7c92d63c1..fbcce675540 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -1748,6 +1748,7 @@ ExecRelCheck(ResultRelInfo *resultRelInfo,
 			Expr	   *checkconstr;
 
 			checkconstr = stringToNode(check[i].ccbin);
+			checkconstr = (Expr *) expand_generated_columns_in_expr((Node *) checkconstr, rel);
 			resultRelInfo->ri_ConstraintExprs[i] =
 				ExecPrepareExpr(checkconstr, estate);
 		}
@@ -2269,6 +2270,10 @@ ExecBuildSlotValueDescription(Oid reloid,
 		if (att->attisdropped)
 			continue;
 
+		/* ignore virtual generated columns; they are always null here */
+		if (att->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
+			continue;
+
 		if (!table_perm)
 		{
 			/*
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index 28fed9d87f6..01dedbfc396 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -562,6 +562,7 @@ transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt)
 	qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
 	qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
 	qry->hasAggs = pstate->p_hasAggs;
+	qry->hasGeneratedVirtual = pstate->p_hasGeneratedVirtual;
 
 	assign_query_collations(pstate, qry);
 
@@ -988,6 +989,7 @@ transformInsertStmt(ParseState *pstate, InsertStmt *stmt)
 
 	qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
 	qry->hasSubLinks = pstate->p_hasSubLinks;
+	qry->hasGeneratedVirtual = pstate->p_hasGeneratedVirtual;
 
 	assign_query_collations(pstate, qry);
 
@@ -1453,6 +1455,7 @@ transformSelectStmt(ParseState *pstate, SelectStmt *stmt)
 	qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
 	qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
 	qry->hasAggs = pstate->p_hasAggs;
+	qry->hasGeneratedVirtual = pstate->p_hasGeneratedVirtual;
 
 	foreach(l, stmt->lockingClause)
 	{
@@ -1679,6 +1682,7 @@ transformValuesClause(ParseState *pstate, SelectStmt *stmt)
 	qry->jointree = makeFromExpr(pstate->p_joinlist, NULL);
 
 	qry->hasSubLinks = pstate->p_hasSubLinks;
+	qry->hasGeneratedVirtual = pstate->p_hasGeneratedVirtual;
 
 	assign_query_collations(pstate, qry);
 
@@ -1930,6 +1934,7 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt)
 	qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
 	qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
 	qry->hasAggs = pstate->p_hasAggs;
+	qry->hasGeneratedVirtual = pstate->p_hasGeneratedVirtual;
 
 	foreach(l, lockingClause)
 	{
@@ -2404,6 +2409,7 @@ transformReturnStmt(ParseState *pstate, ReturnStmt *stmt)
 	qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
 	qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
 	qry->hasAggs = pstate->p_hasAggs;
+	qry->hasGeneratedVirtual = pstate->p_hasGeneratedVirtual;
 
 	assign_query_collations(pstate, qry);
 
@@ -2471,6 +2477,7 @@ transformUpdateStmt(ParseState *pstate, UpdateStmt *stmt)
 
 	qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
 	qry->hasSubLinks = pstate->p_hasSubLinks;
+	qry->hasGeneratedVirtual = pstate->p_hasGeneratedVirtual;
 
 	assign_query_collations(pstate, qry);
 
@@ -2837,6 +2844,7 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt)
 	qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
 	qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
 	qry->hasAggs = pstate->p_hasAggs;
+	qry->hasGeneratedVirtual = pstate->p_hasGeneratedVirtual;
 
 	foreach(l, sstmt->lockingClause)
 	{
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index e8b619926ef..9643b2ae65d 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -642,7 +642,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 %type <str>		opt_existing_window_name
 %type <boolean> opt_if_not_exists
 %type <boolean> opt_unique_null_treatment
-%type <ival>	generated_when override_kind
+%type <ival>	generated_when override_kind opt_virtual_or_stored
 %type <partspec>	PartitionSpec OptPartitionSpec
 %type <partelem>	part_elem
 %type <list>		part_params
@@ -793,7 +793,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 	UNLISTEN UNLOGGED UNTIL UPDATE USER USING
 
 	VACUUM VALID VALIDATE VALIDATOR VALUE_P VALUES VARCHAR VARIADIC VARYING
-	VERBOSE VERSION_P VIEW VIEWS VOLATILE
+	VERBOSE VERSION_P VIEW VIEWS VIRTUAL VOLATILE
 
 	WHEN WHERE WHITESPACE_P WINDOW WITH WITHIN WITHOUT WORK WRAPPER WRITE
 
@@ -4030,7 +4030,7 @@ ColConstraintElem:
 					n->location = @1;
 					$$ = (Node *) n;
 				}
-			| GENERATED generated_when AS '(' a_expr ')' STORED
+			| GENERATED generated_when AS '(' a_expr ')' opt_virtual_or_stored
 				{
 					Constraint *n = makeNode(Constraint);
 
@@ -4038,6 +4038,7 @@ ColConstraintElem:
 					n->generated_when = $2;
 					n->raw_expr = $5;
 					n->cooked_expr = NULL;
+					n->generated_kind = $7;
 					n->location = @1;
 
 					/*
@@ -4084,6 +4085,12 @@ generated_when:
 			| BY DEFAULT	{ $$ = ATTRIBUTE_IDENTITY_BY_DEFAULT; }
 		;
 
+opt_virtual_or_stored:
+			STORED			{ $$ = ATTRIBUTE_GENERATED_STORED; }
+			| VIRTUAL		{ $$ = ATTRIBUTE_GENERATED_VIRTUAL; }
+			| /*EMPTY*/		{ $$ = ATTRIBUTE_GENERATED_VIRTUAL; }
+		;
+
 /*
  * ConstraintAttr represents constraint attributes, which we parse as if
  * they were independent constraint clauses, in order to avoid shift/reduce
@@ -17929,6 +17936,7 @@ unreserved_keyword:
 			| VERSION_P
 			| VIEW
 			| VIEWS
+			| VIRTUAL
 			| VOLATILE
 			| WHITESPACE_P
 			| WITHIN
@@ -18586,6 +18594,7 @@ bare_label_keyword:
 			| VERSION_P
 			| VIEW
 			| VIEWS
+			| VIRTUAL
 			| VOLATILE
 			| WHEN
 			| WHITESPACE_P
diff --git a/src/backend/parser/parse_clause.c b/src/backend/parser/parse_clause.c
index 4fc5fc87e07..0a54eb0c533 100644
--- a/src/backend/parser/parse_clause.c
+++ b/src/backend/parser/parse_clause.c
@@ -207,6 +207,10 @@ setTargetTable(ParseState *pstate, RangeVar *relation,
 	pstate->p_target_relation = parserOpenTable(pstate, relation,
 												RowExclusiveLock);
 
+	if (pstate->p_target_relation->rd_att->constr &&
+		pstate->p_target_relation->rd_att->constr->has_generated_virtual)
+		pstate->p_hasGeneratedVirtual = true;
+
 	/*
 	 * Now build an RTE and a ParseNamespaceItem.
 	 */
diff --git a/src/backend/parser/parse_relation.c b/src/backend/parser/parse_relation.c
index 2f64eaf0e37..b864749f09c 100644
--- a/src/backend/parser/parse_relation.c
+++ b/src/backend/parser/parse_relation.c
@@ -704,7 +704,11 @@ scanNSItemForColumn(ParseState *pstate, ParseNamespaceItem *nsitem,
 						colname),
 				 parser_errposition(pstate, location)));
 
-	/* In generated column, no system column is allowed except tableOid */
+	/*
+	 * In generated column, no system column is allowed except tableOid.
+	 * (Required for stored generated, but we also do it for virtual generated
+	 * for now for consistency.)
+	 */
 	if (pstate->p_expr_kind == EXPR_KIND_GENERATED_COLUMN &&
 		attnum < InvalidAttrNumber && attnum != TableOidAttributeNumber)
 		ereport(ERROR,
@@ -1511,6 +1515,9 @@ addRangeTableEntry(ParseState *pstate,
 	rte->eref = makeAlias(refname, NIL);
 	buildRelationAliases(rel->rd_att, alias, rte->eref);
 
+	if (rel->rd_att->constr && rel->rd_att->constr->has_generated_virtual)
+		pstate->p_hasGeneratedVirtual = true;
+
 	/*
 	 * Set flags and initialize access permissions.
 	 *
diff --git a/src/backend/parser/parse_utilcmd.c b/src/backend/parser/parse_utilcmd.c
index fef084f5d52..ec24fda3015 100644
--- a/src/backend/parser/parse_utilcmd.c
+++ b/src/backend/parser/parse_utilcmd.c
@@ -786,10 +786,33 @@ transformColumnDefinition(CreateStmtContext *cxt, ColumnDef *column)
 									column->colname, cxt->relation->relname),
 							 parser_errposition(cxt->pstate,
 												constraint->location)));
-				column->generated = ATTRIBUTE_GENERATED_STORED;
+				column->generated = constraint->generated_kind;
 				column->raw_default = constraint->raw_expr;
 				Assert(constraint->cooked_expr == NULL);
 				saw_generated = true;
+
+#if FIXME
+				/*
+				 * Prevent virtual generated columns from having a domain
+				 * type.  We would have to enforce domain constraints when
+				 * columns underlying the generated column change.  This could
+				 * possibly be implemented, but it's not.
+				 */
+				if (column->generated == ATTRIBUTE_GENERATED_VIRTUAL)
+				{
+					Type		ctype;
+
+					ctype = typenameType(cxt->pstate, column->typeName, NULL);
+					if (((Form_pg_type) GETSTRUCT(ctype))->typtype == TYPTYPE_DOMAIN)
+						ereport(ERROR,
+								(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+								 errmsg("virtual generated column \"%s\" cannot have a domain type",
+										column->colname),
+								 parser_errposition(cxt->pstate,
+													column->location)));
+					ReleaseSysCache(ctype);
+				}
+#endif
 				break;
 
 			case CONSTR_CHECK:
@@ -874,6 +897,8 @@ transformColumnDefinition(CreateStmtContext *cxt, ColumnDef *column)
 							column->colname, cxt->relation->relname),
 					 parser_errposition(cxt->pstate,
 										constraint->location)));
+
+		// TODO: not-null constraints on virtual generated columns (see v8 patch)
 	}
 
 	/*
diff --git a/src/backend/rewrite/rewriteHandler.c b/src/backend/rewrite/rewriteHandler.c
index 9fd05b15e73..7dc381ecf60 100644
--- a/src/backend/rewrite/rewriteHandler.c
+++ b/src/backend/rewrite/rewriteHandler.c
@@ -90,6 +90,8 @@ static List *matchLocks(CmdType event, Relation relation,
 						int varno, Query *parsetree, bool *hasUpdate);
 static Query *fireRIRrules(Query *parsetree, List *activeRIRs);
 static Bitmapset *adjust_view_column_set(Bitmapset *cols, List *targetlist);
+struct expand_generated_context;
+static Query *expand_generated_columns_in_query(Query *query, struct expand_generated_context *context);
 
 
 /*
@@ -974,7 +976,8 @@ rewriteTargetListIU(List *targetList,
 		if (att_tup->attgenerated)
 		{
 			/*
-			 * stored generated column will be fixed in executor
+			 * virtual generated column stores a null value; stored generated
+			 * column will be fixed in executor
 			 */
 			new_tle = NULL;
 		}
@@ -4358,6 +4361,150 @@ RewriteQuery(Query *parsetree, List *rewrite_events, int orig_rt_length)
 }
 
 
+static Node *
+expand_generated_columns_in_expr_mutator(Node *node, Relation rel)
+{
+	if (node == NULL)
+		return NULL;
+
+	if (IsA(node, Var))
+	{
+		Var		   *v = (Var *) node;
+		AttrNumber	attnum = v->varattno;
+
+		if (attnum > 0 && TupleDescAttr(RelationGetDescr(rel), attnum - 1)->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
+		{
+			node = build_column_default(rel, attnum);
+			if (node == NULL)
+				elog(ERROR, "no generation expression found for column number %d of table \"%s\"",
+					 attnum, RelationGetRelationName(rel));
+			ChangeVarNodes(node, 1, v->varno, 0);
+		}
+
+		return node;
+	}
+	else
+		return expression_tree_mutator(node, expand_generated_columns_in_expr_mutator, rel);
+}
+
+
+Node *
+expand_generated_columns_in_expr(Node *node, Relation rel)
+{
+	TupleDesc	tupdesc = RelationGetDescr(rel);
+
+	if (tupdesc->constr && tupdesc->constr->has_generated_virtual)
+		return expression_tree_mutator(node,
+									   expand_generated_columns_in_expr_mutator,
+									   rel);
+	else
+		return node;
+}
+
+struct expand_generated_context
+{
+	/* list of range tables, innermost last */
+	List	   *rtables;
+};
+
+static Node *
+expand_generated_columns_in_query_mutator(Node *node, struct expand_generated_context *context)
+{
+	if (node == NULL)
+		return NULL;
+
+	if (IsA(node, Var))
+	{
+		Var		   *v = (Var *) node;
+		Oid			relid;
+		AttrNumber	attnum;
+		List	   *rtable = list_nth_node(List,
+										   context->rtables,
+										   list_length(context->rtables) - v->varlevelsup - 1);
+
+		relid = rt_fetch(v->varno, rtable)->relid;
+		attnum = v->varattno;
+
+		if (!relid || !attnum)
+			return node;
+
+		if (get_attgenerated(relid, attnum) == ATTRIBUTE_GENERATED_VIRTUAL)
+		{
+			Relation	rt_entry_relation = table_open(relid, NoLock);
+
+			node = build_column_default(rt_entry_relation, attnum);
+			if (node == NULL)
+				elog(ERROR, "no generation expression found for column number %d of table \"%s\"",
+					 attnum, RelationGetRelationName(rt_entry_relation));
+			ChangeVarNodes(node, 1, v->varno, v->varlevelsup);
+
+			table_close(rt_entry_relation, NoLock);
+		}
+
+		return node;
+	}
+	else if (IsA(node, Query))
+	{
+		Query	   *query = (Query *) node;
+
+		query = expand_generated_columns_in_query(query, context);
+
+		return (Node *) query;
+	}
+	else
+		return expression_tree_mutator(node, expand_generated_columns_in_query_mutator, context);
+}
+
+/*
+ * Expand virtual generated columns in a Query.  We do some optimizations here
+ * to avoid digging through the whole Query unless necessary.
+ */
+static Query *
+expand_generated_columns_in_query(Query *query, struct expand_generated_context *context)
+{
+	context->rtables = lappend(context->rtables, query->rtable);
+
+	/*
+	 * If any table in the query has a virtual column or there is a sublink,
+	 * then we need to do the whole walk.
+	 */
+	if (query->hasGeneratedVirtual || query->hasSubLinks)
+	{
+		query = query_tree_mutator(query,
+								   expand_generated_columns_in_query_mutator,
+								   context,
+								   QTW_DONT_COPY_QUERY);
+	}
+
+	/*
+	 * Else we only need to process subqueries.
+	 */
+	else
+	{
+		ListCell   *lc;
+
+		foreach(lc, query->rtable)
+		{
+			RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc);
+
+			if (rte->rtekind == RTE_SUBQUERY)
+				rte->subquery = expand_generated_columns_in_query(rte->subquery, context);
+		}
+
+		foreach(lc, query->cteList)
+		{
+			CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc);
+
+			cte->ctequery = (Node *) expand_generated_columns_in_query(castNode(Query, cte->ctequery), context);
+		}
+	}
+
+	context->rtables = list_truncate(context->rtables, list_length(context->rtables) - 1);
+
+	return query;
+}
+
+
 /*
  * QueryRewrite -
  *	  Primary entry point to the query rewriter.
@@ -4413,6 +4560,21 @@ QueryRewrite(Query *parsetree)
 	/*
 	 * Step 3
 	 *
+	 * Expand virtual generated columns.
+	 */
+	foreach(l, querylist)
+	{
+		Query	   *query = (Query *) lfirst(l);
+		struct expand_generated_context context;
+
+		context.rtables = NIL;
+
+		query = expand_generated_columns_in_query(query, &context);
+	}
+
+	/*
+	 * Step 4
+	 *
 	 * Determine which, if any, of the resulting queries is supposed to set
 	 * the command-result tag; and update the canSetTag fields accordingly.
 	 *
diff --git a/src/backend/utils/cache/partcache.c b/src/backend/utils/cache/partcache.c
index beec6cddbc4..1dee7c1e899 100644
--- a/src/backend/utils/cache/partcache.c
+++ b/src/backend/utils/cache/partcache.c
@@ -26,6 +26,7 @@
 #include "nodes/nodeFuncs.h"
 #include "optimizer/optimizer.h"
 #include "partitioning/partbounds.h"
+#include "rewrite/rewriteHandler.h"
 #include "utils/builtins.h"
 #include "utils/lsyscache.h"
 #include "utils/memutils.h"
@@ -148,6 +149,8 @@ RelationBuildPartitionKey(Relation relation)
 		expr = stringToNode(exprString);
 		pfree(exprString);
 
+		expr = expand_generated_columns_in_expr(expr, relation);
+
 		/*
 		 * Run the expressions through const-simplification since the planner
 		 * will be comparing them to similarly-processed qual clause operands,
diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index 05c4ae79707..ce6c3712a65 100644
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -588,6 +588,8 @@ RelationBuildTupleDesc(Relation relation)
 			constr->has_not_null = true;
 		if (attp->attgenerated == ATTRIBUTE_GENERATED_STORED)
 			constr->has_generated_stored = true;
+		if (attp->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
+			constr->has_generated_virtual = true;
 		if (attp->atthasdef)
 			ndef++;
 
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 242ebe807f5..4dd52829efe 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -16212,6 +16212,9 @@ dumpTableSchema(Archive *fout, const TableInfo *tbinfo)
 						if (tbinfo->attgenerated[j] == ATTRIBUTE_GENERATED_STORED)
 							appendPQExpBuffer(q, " GENERATED ALWAYS AS (%s) STORED",
 											  tbinfo->attrdefs[j]->adef_expr);
+						else if (tbinfo->attgenerated[j] == ATTRIBUTE_GENERATED_VIRTUAL)
+							appendPQExpBuffer(q, " GENERATED ALWAYS AS (%s)",
+											  tbinfo->attrdefs[j]->adef_expr);
 						else
 							appendPQExpBuffer(q, " DEFAULT %s",
 											  tbinfo->attrdefs[j]->adef_expr);
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index 7085053a2d6..e980829dacc 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -3631,12 +3631,14 @@
 		create_order => 3,
 		create_sql => 'CREATE TABLE dump_test.test_table_generated (
 						   col1 int primary key,
-						   col2 int generated always as (col1 * 2) stored
+						   col2 int generated always as (col1 * 2) stored,
+						   col3 int generated always as (col1 * 3) virtual
 					   );',
 		regexp => qr/^
 			\QCREATE TABLE dump_test.test_table_generated (\E\n
 			\s+\Qcol1 integer CONSTRAINT \E[a-z0-9_]*\Q NOT NULL NO INHERIT,\E\n
-			\s+\Qcol2 integer GENERATED ALWAYS AS ((col1 * 2)) STORED\E\n
+			\s+\Qcol2 integer GENERATED ALWAYS AS ((col1 * 2)) STORED,\E\n
+			\s+\Qcol3 integer GENERATED ALWAYS AS ((col1 * 3))\E\n
 			\);
 			/xms,
 		like =>
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 4a9ee4a54d5..608c0b98fe7 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -2089,6 +2089,12 @@ describeOneTableDetails(const char *schemaname,
 									   PQgetvalue(res, i, attrdef_col));
 				mustfree = true;
 			}
+			else if (generated[0] == ATTRIBUTE_GENERATED_VIRTUAL)
+			{
+				default_str = psprintf("generated always as (%s)",
+									   PQgetvalue(res, i, attrdef_col));
+				mustfree = true;
+			}
 			else
 				default_str = PQgetvalue(res, i, attrdef_col);
 
diff --git a/src/include/access/tupdesc.h b/src/include/access/tupdesc.h
index 8930a28d660..6ef40249583 100644
--- a/src/include/access/tupdesc.h
+++ b/src/include/access/tupdesc.h
@@ -43,6 +43,7 @@ typedef struct TupleConstr
 	uint16		num_check;
 	bool		has_not_null;
 	bool		has_generated_stored;
+	bool		has_generated_virtual;
 } TupleConstr;
 
 /*
diff --git a/src/include/catalog/pg_attribute.h b/src/include/catalog/pg_attribute.h
index 1c62b8bfcb5..8f158dc6083 100644
--- a/src/include/catalog/pg_attribute.h
+++ b/src/include/catalog/pg_attribute.h
@@ -234,6 +234,7 @@ MAKE_SYSCACHE(ATTNUM, pg_attribute_relid_attnum_index, 128);
 #define		  ATTRIBUTE_IDENTITY_BY_DEFAULT 'd'
 
 #define		  ATTRIBUTE_GENERATED_STORED	's'
+#define		  ATTRIBUTE_GENERATED_VIRTUAL	'v'
 
 #endif							/* EXPOSE_TO_CLIENT_CODE */
 
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index af80a5d38e0..ec7b17bcb30 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -160,6 +160,8 @@ typedef struct Query
 	bool		hasForUpdate pg_node_attr(query_jumble_ignore);
 	/* rewriter has applied some RLS policy */
 	bool		hasRowSecurity pg_node_attr(query_jumble_ignore);
+	/* some table has a virtual generated column */
+	bool		hasGeneratedVirtual pg_node_attr(query_jumble_ignore);
 	/* is a RETURN statement */
 	bool		isReturn pg_node_attr(query_jumble_ignore);
 
@@ -2748,6 +2750,7 @@ typedef struct Constraint
 	char	   *cooked_expr;	/* CHECK or DEFAULT expression, as
 								 * nodeToString representation */
 	char		generated_when; /* ALWAYS or BY DEFAULT */
+	char		generated_kind; /* STORED or VIRTUAL */
 	int			inhcount;		/* initial inheritance count to apply, for
 								 * "raw" NOT NULL constraints */
 	bool		nulls_not_distinct; /* null treatment for UNIQUE constraints */
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index f9a4afd4723..1cae2357c28 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -493,6 +493,7 @@ PG_KEYWORD("verbose", VERBOSE, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
 PG_KEYWORD("version", VERSION_P, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("view", VIEW, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("views", VIEWS, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("virtual", VIRTUAL, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("volatile", VOLATILE, UNRESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("when", WHEN, RESERVED_KEYWORD, BARE_LABEL)
 PG_KEYWORD("where", WHERE, RESERVED_KEYWORD, AS_LABEL)
diff --git a/src/include/parser/parse_node.h b/src/include/parser/parse_node.h
index 5b781d87a9d..1b02128548b 100644
--- a/src/include/parser/parse_node.h
+++ b/src/include/parser/parse_node.h
@@ -225,6 +225,7 @@ struct ParseState
 	bool		p_hasTargetSRFs;
 	bool		p_hasSubLinks;
 	bool		p_hasModifyingCTE;
+	bool		p_hasGeneratedVirtual;
 
 	Node	   *p_last_srf;		/* most recent set-returning func/op found */
 
diff --git a/src/include/rewrite/rewriteHandler.h b/src/include/rewrite/rewriteHandler.h
index 1b65cda71cf..a646a20675a 100644
--- a/src/include/rewrite/rewriteHandler.h
+++ b/src/include/rewrite/rewriteHandler.h
@@ -38,4 +38,6 @@ extern void error_view_not_updatable(Relation view,
 									 List *mergeActionList,
 									 const char *detail);
 
+extern Node *expand_generated_columns_in_expr(Node *node, Relation rel);
+
 #endif							/* REWRITEHANDLER_H */
diff --git a/src/pl/plperl/expected/plperl_trigger.out b/src/pl/plperl/expected/plperl_trigger.out
index d4879e2f03b..42c52ecbba8 100644
--- a/src/pl/plperl/expected/plperl_trigger.out
+++ b/src/pl/plperl/expected/plperl_trigger.out
@@ -8,7 +8,8 @@ CREATE TABLE trigger_test (
 );
 CREATE TABLE trigger_test_generated (
     i int,
-    j int GENERATED ALWAYS AS (i * 2) STORED
+    j int GENERATED ALWAYS AS (i * 2) STORED,
+    k int GENERATED ALWAYS AS (i * 3) VIRTUAL
 );
 CREATE OR REPLACE FUNCTION trigger_data() RETURNS trigger LANGUAGE plperl AS $$
 
@@ -386,7 +387,7 @@ INSERT INTO trigger_test_generated (i) VALUES (1);
 ERROR:  cannot set generated column "j"
 CONTEXT:  PL/Perl function "generated_test_func1"
 SELECT * FROM trigger_test_generated;
- i | j 
----+---
+ i | j | k 
+---+---+---
 (0 rows)
 
diff --git a/src/pl/plperl/plperl.c b/src/pl/plperl/plperl.c
index d68ad7be345..9611aa82352 100644
--- a/src/pl/plperl/plperl.c
+++ b/src/pl/plperl/plperl.c
@@ -3052,6 +3052,9 @@ plperl_hash_from_tuple(HeapTuple tuple, TupleDesc tupdesc, bool include_generate
 			/* don't include unless requested */
 			if (!include_generated)
 				continue;
+			/* never include virtual columns */
+			if (att->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
+				continue;
 		}
 
 		attname = NameStr(att->attname);
diff --git a/src/pl/plperl/sql/plperl_trigger.sql b/src/pl/plperl/sql/plperl_trigger.sql
index 4adddeb80ac..2798a02fa12 100644
--- a/src/pl/plperl/sql/plperl_trigger.sql
+++ b/src/pl/plperl/sql/plperl_trigger.sql
@@ -10,7 +10,8 @@ CREATE TABLE trigger_test (
 
 CREATE TABLE trigger_test_generated (
     i int,
-    j int GENERATED ALWAYS AS (i * 2) STORED
+    j int GENERATED ALWAYS AS (i * 2) STORED,
+    k int GENERATED ALWAYS AS (i * 3) VIRTUAL
 );
 
 CREATE OR REPLACE FUNCTION trigger_data() RETURNS trigger LANGUAGE plperl AS $$
diff --git a/src/pl/plpython/expected/plpython_trigger.out b/src/pl/plpython/expected/plpython_trigger.out
index dd1ca32fa49..12f5e15b2a5 100644
--- a/src/pl/plpython/expected/plpython_trigger.out
+++ b/src/pl/plpython/expected/plpython_trigger.out
@@ -69,7 +69,8 @@ CREATE TABLE trigger_test
 	(i int, v text );
 CREATE TABLE trigger_test_generated (
 	i int,
-        j int GENERATED ALWAYS AS (i * 2) STORED
+        j int GENERATED ALWAYS AS (i * 2) STORED,
+        k int GENERATED ALWAYS AS (i * 3) VIRTUAL
 );
 CREATE FUNCTION trigger_data() RETURNS trigger LANGUAGE plpython3u AS $$
 
@@ -614,7 +615,7 @@ ERROR:  cannot set generated column "j"
 CONTEXT:  while modifying trigger row
 PL/Python function "generated_test_func1"
 SELECT * FROM trigger_test_generated;
- i | j 
----+---
+ i | j | k 
+---+---+---
 (0 rows)
 
diff --git a/src/pl/plpython/plpy_typeio.c b/src/pl/plpython/plpy_typeio.c
index db14c5f8dae..51e1d610259 100644
--- a/src/pl/plpython/plpy_typeio.c
+++ b/src/pl/plpython/plpy_typeio.c
@@ -844,6 +844,9 @@ PLyDict_FromTuple(PLyDatumToOb *arg, HeapTuple tuple, TupleDesc desc, bool inclu
 				/* don't include unless requested */
 				if (!include_generated)
 					continue;
+				/* never include virtual columns */
+				if (attr->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
+					continue;
 			}
 
 			key = NameStr(attr->attname);
diff --git a/src/pl/plpython/sql/plpython_trigger.sql b/src/pl/plpython/sql/plpython_trigger.sql
index e5504b9ab1d..d50596a673c 100644
--- a/src/pl/plpython/sql/plpython_trigger.sql
+++ b/src/pl/plpython/sql/plpython_trigger.sql
@@ -69,7 +69,8 @@ CREATE TABLE trigger_test
 
 CREATE TABLE trigger_test_generated (
 	i int,
-        j int GENERATED ALWAYS AS (i * 2) STORED
+        j int GENERATED ALWAYS AS (i * 2) STORED,
+        k int GENERATED ALWAYS AS (i * 3) VIRTUAL
 );
 
 CREATE FUNCTION trigger_data() RETURNS trigger LANGUAGE plpython3u AS $$
diff --git a/src/pl/tcl/expected/pltcl_trigger.out b/src/pl/tcl/expected/pltcl_trigger.out
index 008ea195095..3bf63ba6133 100644
--- a/src/pl/tcl/expected/pltcl_trigger.out
+++ b/src/pl/tcl/expected/pltcl_trigger.out
@@ -63,7 +63,8 @@ CREATE TABLE trigger_test (
 ALTER TABLE trigger_test DROP dropme;
 CREATE TABLE trigger_test_generated (
    i int,
-   j int GENERATED ALWAYS AS (i * 2) STORED
+   j int GENERATED ALWAYS AS (i * 2) STORED,
+   k int GENERATED ALWAYS AS (i * 3) VIRTUAL
 );
 CREATE VIEW trigger_test_view AS SELECT i, v FROM trigger_test;
 CREATE FUNCTION trigger_data() returns trigger language pltcl as $_$
@@ -647,7 +648,7 @@ NOTICE:  OLD: {}
 NOTICE:  TG_level: ROW
 NOTICE:  TG_name: show_trigger_data_trig_before
 NOTICE:  TG_op: INSERT
-NOTICE:  TG_relatts: {{} i j}
+NOTICE:  TG_relatts: {{} i j k}
 NOTICE:  TG_relid: bogus:12345
 NOTICE:  TG_table_name: trigger_test_generated
 NOTICE:  TG_table_schema: public
@@ -658,7 +659,7 @@ NOTICE:  OLD: {}
 NOTICE:  TG_level: ROW
 NOTICE:  TG_name: show_trigger_data_trig_after
 NOTICE:  TG_op: INSERT
-NOTICE:  TG_relatts: {{} i j}
+NOTICE:  TG_relatts: {{} i j k}
 NOTICE:  TG_relid: bogus:12345
 NOTICE:  TG_table_name: trigger_test_generated
 NOTICE:  TG_table_schema: public
@@ -670,7 +671,7 @@ NOTICE:  OLD: {i: 1, j: 2}
 NOTICE:  TG_level: ROW
 NOTICE:  TG_name: show_trigger_data_trig_before
 NOTICE:  TG_op: UPDATE
-NOTICE:  TG_relatts: {{} i j}
+NOTICE:  TG_relatts: {{} i j k}
 NOTICE:  TG_relid: bogus:12345
 NOTICE:  TG_table_name: trigger_test_generated
 NOTICE:  TG_table_schema: public
@@ -681,7 +682,7 @@ NOTICE:  OLD: {i: 1, j: 2}
 NOTICE:  TG_level: ROW
 NOTICE:  TG_name: show_trigger_data_trig_after
 NOTICE:  TG_op: UPDATE
-NOTICE:  TG_relatts: {{} i j}
+NOTICE:  TG_relatts: {{} i j k}
 NOTICE:  TG_relid: bogus:12345
 NOTICE:  TG_table_name: trigger_test_generated
 NOTICE:  TG_table_schema: public
@@ -693,7 +694,7 @@ NOTICE:  OLD: {i: 11, j: 22}
 NOTICE:  TG_level: ROW
 NOTICE:  TG_name: show_trigger_data_trig_before
 NOTICE:  TG_op: DELETE
-NOTICE:  TG_relatts: {{} i j}
+NOTICE:  TG_relatts: {{} i j k}
 NOTICE:  TG_relid: bogus:12345
 NOTICE:  TG_table_name: trigger_test_generated
 NOTICE:  TG_table_schema: public
@@ -704,7 +705,7 @@ NOTICE:  OLD: {i: 11, j: 22}
 NOTICE:  TG_level: ROW
 NOTICE:  TG_name: show_trigger_data_trig_after
 NOTICE:  TG_op: DELETE
-NOTICE:  TG_relatts: {{} i j}
+NOTICE:  TG_relatts: {{} i j k}
 NOTICE:  TG_relid: bogus:12345
 NOTICE:  TG_table_name: trigger_test_generated
 NOTICE:  TG_table_schema: public
@@ -882,7 +883,7 @@ TRUNCATE trigger_test_generated;
 INSERT INTO trigger_test_generated (i) VALUES (1);
 ERROR:  cannot set generated column "j"
 SELECT * FROM trigger_test_generated;
- i | j 
----+---
+ i | j | k 
+---+---+---
 (0 rows)
 
diff --git a/src/pl/tcl/pltcl.c b/src/pl/tcl/pltcl.c
index 18d14a2b982..fc2399fc978 100644
--- a/src/pl/tcl/pltcl.c
+++ b/src/pl/tcl/pltcl.c
@@ -3114,6 +3114,9 @@ pltcl_build_tuple_argument(HeapTuple tuple, TupleDesc tupdesc, bool include_gene
 			/* don't include unless requested */
 			if (!include_generated)
 				continue;
+			/* never include virtual columns */
+			if (att->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL)
+				continue;
 		}
 
 		/************************************************************
diff --git a/src/pl/tcl/sql/pltcl_trigger.sql b/src/pl/tcl/sql/pltcl_trigger.sql
index 2db75a333a0..e4acf6a5fd9 100644
--- a/src/pl/tcl/sql/pltcl_trigger.sql
+++ b/src/pl/tcl/sql/pltcl_trigger.sql
@@ -73,7 +73,8 @@ CREATE TABLE trigger_test (
 
 CREATE TABLE trigger_test_generated (
    i int,
-   j int GENERATED ALWAYS AS (i * 2) STORED
+   j int GENERATED ALWAYS AS (i * 2) STORED,
+   k int GENERATED ALWAYS AS (i * 3) VIRTUAL
 );
 
 CREATE VIEW trigger_test_view AS SELECT i, v FROM trigger_test;
diff --git a/src/test/regress/expected/create_table_like.out b/src/test/regress/expected/create_table_like.out
index 61956773ffd..9d36904c622 100644
--- a/src/test/regress/expected/create_table_like.out
+++ b/src/test/regress/expected/create_table_like.out
@@ -113,19 +113,20 @@ SELECT * FROM test_like_id_3;  -- identity was copied and applied
 (1 row)
 
 DROP TABLE test_like_id_1, test_like_id_2, test_like_id_3;
-CREATE TABLE test_like_gen_1 (a int, b int GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE test_like_gen_1 (a int, b int GENERATED ALWAYS AS (a * 2) STORED, c int GENERATED ALWAYS AS (a * 3) VIRTUAL);
 \d test_like_gen_1
                         Table "public.test_like_gen_1"
  Column |  Type   | Collation | Nullable |              Default               
 --------+---------+-----------+----------+------------------------------------
  a      | integer |           |          | 
  b      | integer |           |          | generated always as (a * 2) stored
+ c      | integer |           |          | generated always as (a * 3)
 
 INSERT INTO test_like_gen_1 (a) VALUES (1);
 SELECT * FROM test_like_gen_1;
- a | b 
----+---
- 1 | 2
+ a | b | c 
+---+---+---
+ 1 | 2 | 3
 (1 row)
 
 CREATE TABLE test_like_gen_2 (LIKE test_like_gen_1);
@@ -135,12 +136,13 @@ CREATE TABLE test_like_gen_2 (LIKE test_like_gen_1);
 --------+---------+-----------+----------+---------
  a      | integer |           |          | 
  b      | integer |           |          | 
+ c      | integer |           |          | 
 
 INSERT INTO test_like_gen_2 (a) VALUES (1);
 SELECT * FROM test_like_gen_2;
- a | b 
----+---
- 1 |  
+ a | b | c 
+---+---+---
+ 1 |   |  
 (1 row)
 
 CREATE TABLE test_like_gen_3 (LIKE test_like_gen_1 INCLUDING GENERATED);
@@ -150,12 +152,13 @@ CREATE TABLE test_like_gen_3 (LIKE test_like_gen_1 INCLUDING GENERATED);
 --------+---------+-----------+----------+------------------------------------
  a      | integer |           |          | 
  b      | integer |           |          | generated always as (a * 2) stored
+ c      | integer |           |          | generated always as (a * 3)
 
 INSERT INTO test_like_gen_3 (a) VALUES (1);
 SELECT * FROM test_like_gen_3;
- a | b 
----+---
- 1 | 2
+ a | b | c 
+---+---+---
+ 1 | 2 | 3
 (1 row)
 
 DROP TABLE test_like_gen_1, test_like_gen_2, test_like_gen_3;
diff --git a/src/test/regress/expected/generated_stored.out b/src/test/regress/expected/generated_stored.out
index 6682092124c..7d230925f89 100644
--- a/src/test/regress/expected/generated_stored.out
+++ b/src/test/regress/expected/generated_stored.out
@@ -1,5 +1,5 @@
 -- sanity check of system catalog
-SELECT attrelid, attname, attgenerated FROM pg_attribute WHERE attgenerated NOT IN ('', 's');
+SELECT attrelid, attname, attgenerated FROM pg_attribute WHERE attgenerated NOT IN ('', 's', 'v');
  attrelid | attname | attgenerated 
 ----------+---------+--------------
 (0 rows)
diff --git a/src/test/regress/expected/generated_stored.out b/src/test/regress/expected/generated_virtual.out
similarity index 71%
copy from src/test/regress/expected/generated_stored.out
copy to src/test/regress/expected/generated_virtual.out
index 6682092124c..ff27feba435 100644
--- a/src/test/regress/expected/generated_stored.out
+++ b/src/test/regress/expected/generated_virtual.out
@@ -1,15 +1,15 @@
 -- sanity check of system catalog
-SELECT attrelid, attname, attgenerated FROM pg_attribute WHERE attgenerated NOT IN ('', 's');
+SELECT attrelid, attname, attgenerated FROM pg_attribute WHERE attgenerated NOT IN ('', 's', 'v');
  attrelid | attname | attgenerated 
 ----------+---------+--------------
 (0 rows)
 
-CREATE SCHEMA generated_stored_tests;
-GRANT USAGE ON SCHEMA generated_stored_tests TO PUBLIC;
-SET search_path = generated_stored_tests;
-CREATE TABLE gtest0 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (55) STORED);
-CREATE TABLE gtest1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED);
-SELECT table_name, column_name, column_default, is_nullable, is_generated, generation_expression FROM information_schema.columns WHERE table_schema = 'generated_stored_tests' ORDER BY 1, 2;
+CREATE SCHEMA generated_virtual_tests;
+GRANT USAGE ON SCHEMA generated_virtual_tests TO PUBLIC;
+SET search_path = generated_virtual_tests;
+CREATE TABLE gtest0 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (55) VIRTUAL);
+CREATE TABLE gtest1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL);
+SELECT table_name, column_name, column_default, is_nullable, is_generated, generation_expression FROM information_schema.columns WHERE table_schema = 'generated_virtual_tests' ORDER BY 1, 2;
  table_name | column_name | column_default | is_nullable | is_generated | generation_expression 
 ------------+-------------+----------------+-------------+--------------+-----------------------
  gtest0     | a           |                | NO          | NEVER        | 
@@ -18,89 +18,89 @@ SELECT table_name, column_name, column_default, is_nullable, is_generated, gener
  gtest1     | b           |                | YES         | ALWAYS       | (a * 2)
 (4 rows)
 
-SELECT table_name, column_name, dependent_column FROM information_schema.column_column_usage WHERE table_schema = 'generated_stored_tests' ORDER BY 1, 2, 3;
+SELECT table_name, column_name, dependent_column FROM information_schema.column_column_usage WHERE table_schema = 'generated_virtual_tests' ORDER BY 1, 2, 3;
  table_name | column_name | dependent_column 
 ------------+-------------+------------------
  gtest1     | a           | b
 (1 row)
 
 \d gtest1
-                    Table "generated_stored_tests.gtest1"
- Column |  Type   | Collation | Nullable |              Default               
---------+---------+-----------+----------+------------------------------------
+                Table "generated_virtual_tests.gtest1"
+ Column |  Type   | Collation | Nullable |           Default           
+--------+---------+-----------+----------+-----------------------------
  a      | integer |           | not null | 
- b      | integer |           |          | generated always as (a * 2) stored
+ b      | integer |           |          | generated always as (a * 2)
 Indexes:
     "gtest1_pkey" PRIMARY KEY, btree (a)
 
 -- duplicate generated
-CREATE TABLE gtest_err_1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED GENERATED ALWAYS AS (a * 3) STORED);
+CREATE TABLE gtest_err_1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL GENERATED ALWAYS AS (a * 3) VIRTUAL);
 ERROR:  multiple generation clauses specified for column "b" of table "gtest_err_1"
-LINE 1: ...ARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED GENERATED ...
+LINE 1: ...RY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL GENERATED ...
                                                              ^
 -- references to other generated columns, including self-references
-CREATE TABLE gtest_err_2a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (b * 2) STORED);
+CREATE TABLE gtest_err_2a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (b * 2) VIRTUAL);
 ERROR:  cannot use generated column "b" in column generation expression
-LINE 1: ...2a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (b * 2) STO...
+LINE 1: ...2a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (b * 2) VIR...
                                                              ^
 DETAIL:  A generated column cannot reference another generated column.
-CREATE TABLE gtest_err_2b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED, c int GENERATED ALWAYS AS (b * 3) STORED);
+CREATE TABLE gtest_err_2b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL, c int GENERATED ALWAYS AS (b * 3) VIRTUAL);
 ERROR:  cannot use generated column "b" in column generation expression
-LINE 1: ...AYS AS (a * 2) STORED, c int GENERATED ALWAYS AS (b * 3) STO...
+LINE 1: ...YS AS (a * 2) VIRTUAL, c int GENERATED ALWAYS AS (b * 3) VIR...
                                                              ^
 DETAIL:  A generated column cannot reference another generated column.
 -- a whole-row var is a self-reference on steroids, so disallow that too
 CREATE TABLE gtest_err_2c (a int PRIMARY KEY,
-    b int GENERATED ALWAYS AS (num_nulls(gtest_err_2c)) STORED);
+    b int GENERATED ALWAYS AS (num_nulls(gtest_err_2c)) VIRTUAL);
 ERROR:  cannot use whole-row variable in column generation expression
-LINE 2:     b int GENERATED ALWAYS AS (num_nulls(gtest_err_2c)) STOR...
+LINE 2:     b int GENERATED ALWAYS AS (num_nulls(gtest_err_2c)) VIRT...
                                                  ^
 DETAIL:  This would cause the generated column to depend on its own value.
 -- invalid reference
-CREATE TABLE gtest_err_3 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (c * 2) STORED);
+CREATE TABLE gtest_err_3 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (c * 2) VIRTUAL);
 ERROR:  column "c" does not exist
-LINE 1: ..._3 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (c * 2) STO...
+LINE 1: ..._3 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (c * 2) VIR...
                                                              ^
 -- generation expression must be immutable
-CREATE TABLE gtest_err_4 (a int PRIMARY KEY, b double precision GENERATED ALWAYS AS (random()) STORED);
+CREATE TABLE gtest_err_4 (a int PRIMARY KEY, b double precision GENERATED ALWAYS AS (random()) VIRTUAL);
 ERROR:  generation expression is not immutable
 -- ... but be sure that the immutability test is accurate
-CREATE TABLE gtest2 (a int, b text GENERATED ALWAYS AS (a || ' sec') STORED);
+CREATE TABLE gtest2 (a int, b text GENERATED ALWAYS AS (a || ' sec') VIRTUAL);
 DROP TABLE gtest2;
 -- cannot have default/identity and generated
-CREATE TABLE gtest_err_5a (a int PRIMARY KEY, b int DEFAULT 5 GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE gtest_err_5a (a int PRIMARY KEY, b int DEFAULT 5 GENERATED ALWAYS AS (a * 2) VIRTUAL);
 ERROR:  both default and generation expression specified for column "b" of table "gtest_err_5a"
 LINE 1: ... gtest_err_5a (a int PRIMARY KEY, b int DEFAULT 5 GENERATED ...
                                                              ^
-CREATE TABLE gtest_err_5b (a int PRIMARY KEY, b int GENERATED ALWAYS AS identity GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE gtest_err_5b (a int PRIMARY KEY, b int GENERATED ALWAYS AS identity GENERATED ALWAYS AS (a * 2) VIRTUAL);
 ERROR:  both identity and generation expression specified for column "b" of table "gtest_err_5b"
 LINE 1: ...t PRIMARY KEY, b int GENERATED ALWAYS AS identity GENERATED ...
                                                              ^
 -- reference to system column not allowed in generated column
 -- (except tableoid, which we test below)
-CREATE TABLE gtest_err_6a (a int PRIMARY KEY, b bool GENERATED ALWAYS AS (xmin <> 37) STORED);
+CREATE TABLE gtest_err_6a (a int PRIMARY KEY, b bool GENERATED ALWAYS AS (xmin <> 37) VIRTUAL);
 ERROR:  cannot use system column "xmin" in column generation expression
 LINE 1: ...a (a int PRIMARY KEY, b bool GENERATED ALWAYS AS (xmin <> 37...
                                                              ^
 -- various prohibited constructs
-CREATE TABLE gtest_err_7a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (avg(a)) STORED);
+CREATE TABLE gtest_err_7a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (avg(a)) VIRTUAL);
 ERROR:  aggregate functions are not allowed in column generation expressions
-LINE 1: ...7a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (avg(a)) ST...
+LINE 1: ...7a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (avg(a)) VI...
                                                              ^
-CREATE TABLE gtest_err_7b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (row_number() OVER (ORDER BY a)) STORED);
+CREATE TABLE gtest_err_7b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (row_number() OVER (ORDER BY a)) VIRTUAL);
 ERROR:  window functions are not allowed in column generation expressions
 LINE 1: ...7b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (row_number...
                                                              ^
-CREATE TABLE gtest_err_7c (a int PRIMARY KEY, b int GENERATED ALWAYS AS ((SELECT a)) STORED);
+CREATE TABLE gtest_err_7c (a int PRIMARY KEY, b int GENERATED ALWAYS AS ((SELECT a)) VIRTUAL);
 ERROR:  cannot use subquery in column generation expression
 LINE 1: ...7c (a int PRIMARY KEY, b int GENERATED ALWAYS AS ((SELECT a)...
                                                              ^
-CREATE TABLE gtest_err_7d (a int PRIMARY KEY, b int GENERATED ALWAYS AS (generate_series(1, a)) STORED);
+CREATE TABLE gtest_err_7d (a int PRIMARY KEY, b int GENERATED ALWAYS AS (generate_series(1, a)) VIRTUAL);
 ERROR:  set-returning functions are not allowed in column generation expressions
 LINE 1: ...7d (a int PRIMARY KEY, b int GENERATED ALWAYS AS (generate_s...
                                                              ^
 -- GENERATED BY DEFAULT not allowed
-CREATE TABLE gtest_err_8 (a int PRIMARY KEY, b int GENERATED BY DEFAULT AS (a * 2) STORED);
+CREATE TABLE gtest_err_8 (a int PRIMARY KEY, b int GENERATED BY DEFAULT AS (a * 2) VIRTUAL);
 ERROR:  for a generated column, GENERATED ALWAYS must be specified
 LINE 1: ...E gtest_err_8 (a int PRIMARY KEY, b int GENERATED BY DEFAULT...
                                                              ^
@@ -153,16 +153,10 @@ SELECT a, b FROM gtest1 WHERE b = 4 ORDER BY a;
  2 | 4
 (1 row)
 
--- test that overflow error happens on write
+-- test that overflow error happens on read
 INSERT INTO gtest1 VALUES (2000000000);
-ERROR:  integer out of range
 SELECT * FROM gtest1;
- a | b 
----+---
- 2 | 4
- 1 | 2
-(2 rows)
-
+ERROR:  integer out of range
 DELETE FROM gtest1 WHERE a = 2000000000;
 -- test with joins
 CREATE TABLE gtestx (x int, y int);
@@ -203,8 +197,8 @@ CREATE TABLE gtestm (
   id int PRIMARY KEY,
   f1 int,
   f2 int,
-  f3 int GENERATED ALWAYS AS (f1 * 2) STORED,
-  f4 int GENERATED ALWAYS AS (f2 * 2) STORED
+  f3 int GENERATED ALWAYS AS (f1 * 2) VIRTUAL,
+  f4 int GENERATED ALWAYS AS (f2 * 2) VIRTUAL
 );
 INSERT INTO gtestm VALUES (1, 5, 100);
 MERGE INTO gtestm t USING (VALUES (1, 10), (2, 20)) v(id, f1) ON t.id = v.id
@@ -273,11 +267,11 @@ SELECT * FROM gtest1_1;
 (0 rows)
 
 \d gtest1_1
-                   Table "generated_stored_tests.gtest1_1"
- Column |  Type   | Collation | Nullable |              Default               
---------+---------+-----------+----------+------------------------------------
+               Table "generated_virtual_tests.gtest1_1"
+ Column |  Type   | Collation | Nullable |           Default           
+--------+---------+-----------+----------+-----------------------------
  a      | integer |           | not null | 
- b      | integer |           |          | generated always as (a * 2) stored
+ b      | integer |           |          | generated always as (a * 2)
 Inherits: gtest1
 
 INSERT INTO gtest1_1 VALUES (4);
@@ -296,12 +290,12 @@ SELECT * FROM gtest1;
 
 -- can't have generated column that is a child of normal column
 CREATE TABLE gtest_normal (a int, b int);
-CREATE TABLE gtest_normal_child (a int, b int GENERATED ALWAYS AS (a * 2) STORED) INHERITS (gtest_normal);  -- error
+CREATE TABLE gtest_normal_child (a int, b int GENERATED ALWAYS AS (a * 2) VIRTUAL) INHERITS (gtest_normal);  -- error
 NOTICE:  merging column "a" with inherited definition
 NOTICE:  merging column "b" with inherited definition
 ERROR:  child column "b" specifies generation expression
 HINT:  A child table column cannot be generated unless its parent column is.
-CREATE TABLE gtest_normal_child (a int, b int GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE gtest_normal_child (a int, b int GENERATED ALWAYS AS (a * 2) VIRTUAL);
 ALTER TABLE gtest_normal_child INHERIT gtest_normal;  -- error
 ERROR:  column "b" in child table must not be a generated column
 DROP TABLE gtest_normal, gtest_normal_child;
@@ -312,15 +306,15 @@ ERROR:  column "b" inherits from generated column but specifies default
 CREATE TABLE gtestx (x int, b int GENERATED ALWAYS AS IDENTITY) INHERITS (gtest1);  -- error
 NOTICE:  merging column "b" with inherited definition
 ERROR:  column "b" inherits from generated column but specifies identity
-CREATE TABLE gtestx (x int, b int GENERATED ALWAYS AS (a * 22) STORED) INHERITS (gtest1);  -- ok, overrides parent
+CREATE TABLE gtestx (x int, b int GENERATED ALWAYS AS (a * 22) VIRTUAL) INHERITS (gtest1);  -- ok, overrides parent
 NOTICE:  merging column "b" with inherited definition
 \d+ gtestx
-                                        Table "generated_stored_tests.gtestx"
- Column |  Type   | Collation | Nullable |               Default               | Storage | Stats target | Description 
---------+---------+-----------+----------+-------------------------------------+---------+--------------+-------------
- a      | integer |           | not null |                                     | plain   |              | 
- b      | integer |           |          | generated always as (a * 22) stored | plain   |              | 
- x      | integer |           |          |                                     | plain   |              | 
+                                    Table "generated_virtual_tests.gtestx"
+ Column |  Type   | Collation | Nullable |           Default            | Storage | Stats target | Description 
+--------+---------+-----------+----------+------------------------------+---------+--------------+-------------
+ a      | integer |           | not null |                              | plain   |              | 
+ b      | integer |           |          | generated always as (a * 22) | plain   |              | 
+ x      | integer |           |          |                              | plain   |              | 
 Not-null constraints:
     "gtestx_a_not_null" NOT NULL "a" (inherited)
 Inherits: gtest1
@@ -328,9 +322,9 @@ Inherits: gtest1
 CREATE TABLE gtestxx_1 (a int NOT NULL, b int);
 ALTER TABLE gtestxx_1 INHERIT gtest1;  -- error
 ERROR:  column "b" in child table must be a generated column
-CREATE TABLE gtestxx_3 (a int NOT NULL, b int GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE gtestxx_3 (a int NOT NULL, b int GENERATED ALWAYS AS (a * 2) VIRTUAL);
 ALTER TABLE gtestxx_3 INHERIT gtest1;  -- ok
-CREATE TABLE gtestxx_4 (b int GENERATED ALWAYS AS (a * 2) STORED, a int NOT NULL);
+CREATE TABLE gtestxx_4 (b int GENERATED ALWAYS AS (a * 2) VIRTUAL, a int NOT NULL);
 ALTER TABLE gtestxx_4 INHERIT gtest1;  -- ok
 -- test multiple inheritance mismatches
 CREATE TABLE gtesty (x int, b int DEFAULT 55);
@@ -343,28 +337,28 @@ CREATE TABLE gtest1_y () INHERITS (gtest1, gtesty);  -- error
 NOTICE:  merging multiple inherited definitions of column "b"
 ERROR:  inherited column "b" has a generation conflict
 DROP TABLE gtesty;
-CREATE TABLE gtesty (x int, b int GENERATED ALWAYS AS (x * 22) STORED);
+CREATE TABLE gtesty (x int, b int GENERATED ALWAYS AS (x * 22) VIRTUAL);
 CREATE TABLE gtest1_y () INHERITS (gtest1, gtesty);  -- error
 NOTICE:  merging multiple inherited definitions of column "b"
 ERROR:  column "b" inherits conflicting generation expressions
 HINT:  To resolve the conflict, specify a generation expression explicitly.
-CREATE TABLE gtest1_y (b int GENERATED ALWAYS AS (x + 1) STORED) INHERITS (gtest1, gtesty);  -- ok
+CREATE TABLE gtest1_y (b int GENERATED ALWAYS AS (x + 1) VIRTUAL) INHERITS (gtest1, gtesty);  -- ok
 NOTICE:  merging multiple inherited definitions of column "b"
 NOTICE:  moving and merging column "b" with inherited definition
 DETAIL:  User-specified column moved to the position of the inherited column.
 \d gtest1_y
-                   Table "generated_stored_tests.gtest1_y"
- Column |  Type   | Collation | Nullable |              Default               
---------+---------+-----------+----------+------------------------------------
+               Table "generated_virtual_tests.gtest1_y"
+ Column |  Type   | Collation | Nullable |           Default           
+--------+---------+-----------+----------+-----------------------------
  a      | integer |           | not null | 
- b      | integer |           |          | generated always as (x + 1) stored
+ b      | integer |           |          | generated always as (x + 1)
  x      | integer |           |          | 
 Inherits: gtest1,
           gtesty
 
 -- test correct handling of GENERATED column that's only in child
 CREATE TABLE gtestp (f1 int);
-CREATE TABLE gtestc (f2 int GENERATED ALWAYS AS (f1+1) STORED) INHERITS(gtestp);
+CREATE TABLE gtestc (f2 int GENERATED ALWAYS AS (f1+1) VIRTUAL) INHERITS(gtestp);
 INSERT INTO gtestc values(42);
 TABLE gtestc;
  f1 | f2 
@@ -381,8 +375,8 @@ TABLE gtestc;
 
 DROP TABLE gtestp CASCADE;
 NOTICE:  drop cascades to table gtestc
--- test stored update
-CREATE TABLE gtest3 (a int, b int GENERATED ALWAYS AS (a * 3) STORED);
+-- test update XXX
+CREATE TABLE gtest3 (a int, b int GENERATED ALWAYS AS (a * 3) VIRTUAL);
 INSERT INTO gtest3 (a) VALUES (1), (2), (3), (NULL);
 SELECT * FROM gtest3 ORDER BY a;
  a | b 
@@ -403,7 +397,7 @@ SELECT * FROM gtest3 ORDER BY a;
     |   
 (4 rows)
 
-CREATE TABLE gtest3a (a text, b text GENERATED ALWAYS AS (a || '+' || a) STORED);
+CREATE TABLE gtest3a (a text, b text GENERATED ALWAYS AS (a || '+' || a) VIRTUAL);
 INSERT INTO gtest3a (a) VALUES ('a'), ('b'), ('c'), (NULL);
 SELECT * FROM gtest3a ORDER BY a;
  a |  b  
@@ -468,7 +462,7 @@ SELECT * FROM gtest3 ORDER BY a;
 (4 rows)
 
 -- null values
-CREATE TABLE gtest2 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (NULL) STORED);
+CREATE TABLE gtest2 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (NULL) VIRTUAL);
 INSERT INTO gtest2 VALUES (1);
 SELECT * FROM gtest2;
  a | b 
@@ -477,7 +471,7 @@ SELECT * FROM gtest2;
 (1 row)
 
 -- simple column reference for varlena types
-CREATE TABLE gtest_varlena (a varchar, b varchar GENERATED ALWAYS AS (a) STORED);
+CREATE TABLE gtest_varlena (a varchar, b varchar GENERATED ALWAYS AS (a) VIRTUAL);
 INSERT INTO gtest_varlena (a) VALUES('01234567890123456789');
 INSERT INTO gtest_varlena (a) VALUES(NULL);
 SELECT * FROM gtest_varlena ORDER BY a;
@@ -492,7 +486,7 @@ DROP TABLE gtest_varlena;
 CREATE TYPE double_int as (a int, b int);
 CREATE TABLE gtest4 (
     a int,
-    b double_int GENERATED ALWAYS AS ((a * 2, a * 3)) STORED
+    b double_int GENERATED ALWAYS AS ((a * 2, a * 3)) VIRTUAL
 );
 INSERT INTO gtest4 VALUES (1), (6);
 SELECT * FROM gtest4;
@@ -507,11 +501,11 @@ DROP TYPE double_int;
 -- using tableoid is allowed
 CREATE TABLE gtest_tableoid (
   a int PRIMARY KEY,
-  b bool GENERATED ALWAYS AS (tableoid = 'gtest_tableoid'::regclass) STORED
+  b bool GENERATED ALWAYS AS (tableoid = 'gtest_tableoid'::regclass) VIRTUAL
 );
 INSERT INTO gtest_tableoid VALUES (1), (2);
 ALTER TABLE gtest_tableoid ADD COLUMN
-  c regclass GENERATED ALWAYS AS (tableoid) STORED;
+  c regclass GENERATED ALWAYS AS (tableoid) VIRTUAL;
 SELECT * FROM gtest_tableoid;
  a | b |       c        
 ---+---+----------------
@@ -520,7 +514,7 @@ SELECT * FROM gtest_tableoid;
 (2 rows)
 
 -- drop column behavior
-CREATE TABLE gtest10 (a int PRIMARY KEY, b int, c int GENERATED ALWAYS AS (b * 2) STORED);
+CREATE TABLE gtest10 (a int PRIMARY KEY, b int, c int GENERATED ALWAYS AS (b * 2) VIRTUAL);
 ALTER TABLE gtest10 DROP COLUMN b;  -- fails
 ERROR:  cannot drop column b of table gtest10 because other objects depend on it
 DETAIL:  column c of table gtest10 depends on column b of table gtest10
@@ -528,30 +522,31 @@ HINT:  Use DROP ... CASCADE to drop the dependent objects too.
 ALTER TABLE gtest10 DROP COLUMN b CASCADE;  -- drops c too
 NOTICE:  drop cascades to column c of table gtest10
 \d gtest10
-      Table "generated_stored_tests.gtest10"
+      Table "generated_virtual_tests.gtest10"
  Column |  Type   | Collation | Nullable | Default 
 --------+---------+-----------+----------+---------
  a      | integer |           | not null | 
 Indexes:
     "gtest10_pkey" PRIMARY KEY, btree (a)
 
-CREATE TABLE gtest10a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE gtest10a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL);
 ALTER TABLE gtest10a DROP COLUMN b;
 INSERT INTO gtest10a (a) VALUES (1);
 -- privileges
 CREATE USER regress_user11;
-CREATE TABLE gtest11s (a int PRIMARY KEY, b int, c int GENERATED ALWAYS AS (b * 2) STORED);
-INSERT INTO gtest11s VALUES (1, 10), (2, 20);
-GRANT SELECT (a, c) ON gtest11s TO regress_user11;
+CREATE TABLE gtest11v (a int PRIMARY KEY, b int, c int GENERATED ALWAYS AS (b * 2) VIRTUAL);
+INSERT INTO gtest11v VALUES (1, 10), (2, 20);
+GRANT SELECT (a, c) ON gtest11v TO regress_user11;
 CREATE FUNCTION gf1(a int) RETURNS int AS $$ SELECT a * 3 $$ IMMUTABLE LANGUAGE SQL;
 REVOKE ALL ON FUNCTION gf1(int) FROM PUBLIC;
-CREATE TABLE gtest12s (a int PRIMARY KEY, b int, c int GENERATED ALWAYS AS (gf1(b)) STORED);
-INSERT INTO gtest12s VALUES (1, 10), (2, 20);
+CREATE TABLE gtest12v (a int PRIMARY KEY, b int, c int GENERATED ALWAYS AS (gf1(b)) VIRTUAL);
+INSERT INTO gtest12v VALUES (1, 10), (2, 20);
 GRANT SELECT (a, c) ON gtest12s TO regress_user11;
+ERROR:  relation "gtest12s" does not exist
 SET ROLE regress_user11;
-SELECT a, b FROM gtest11s;  -- not allowed
-ERROR:  permission denied for table gtest11s
-SELECT a, c FROM gtest11s;  -- allowed
+SELECT a, b FROM gtest11v;  -- not allowed
+ERROR:  permission denied for table gtest11v
+SELECT a, c FROM gtest11v;  -- allowed
  a | c  
 ---+----
  1 | 20
@@ -560,231 +555,139 @@ SELECT a, c FROM gtest11s;  -- allowed
 
 SELECT gf1(10);  -- not allowed
 ERROR:  permission denied for function gf1
-SELECT a, c FROM gtest12s;  -- allowed
- a | c  
----+----
- 1 | 30
- 2 | 60
-(2 rows)
-
+SELECT a, c FROM gtest12v;  -- not allowed; TODO: ought to be allowed
+ERROR:  permission denied for table gtest12v
 RESET ROLE;
 DROP FUNCTION gf1(int);  -- fail
 ERROR:  cannot drop function gf1(integer) because other objects depend on it
-DETAIL:  column c of table gtest12s depends on function gf1(integer)
+DETAIL:  column c of table gtest12v depends on function gf1(integer)
 HINT:  Use DROP ... CASCADE to drop the dependent objects too.
-DROP TABLE gtest11s, gtest12s;
+DROP TABLE gtest11v, gtest12v;
 DROP FUNCTION gf1(int);
 DROP USER regress_user11;
 -- check constraints
-CREATE TABLE gtest20 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED CHECK (b < 50));
+CREATE TABLE gtest20 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL CHECK (b < 50));
 INSERT INTO gtest20 (a) VALUES (10);  -- ok
 INSERT INTO gtest20 (a) VALUES (30);  -- violates constraint
 ERROR:  new row for relation "gtest20" violates check constraint "gtest20_b_check"
-DETAIL:  Failing row contains (30, 60).
+DETAIL:  Failing row contains (30).
 ALTER TABLE gtest20 ALTER COLUMN b SET EXPRESSION AS (a * 100);  -- violates constraint
-ERROR:  check constraint "gtest20_b_check" of relation "gtest20" is violated by some row
+ERROR:  column "b" of relation "gtest20" is not a generated column
 ALTER TABLE gtest20 ALTER COLUMN b SET EXPRESSION AS (a * 3);  -- ok
-CREATE TABLE gtest20a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED);
+ERROR:  column "b" of relation "gtest20" is not a generated column
+CREATE TABLE gtest20a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL);
 INSERT INTO gtest20a (a) VALUES (10);
 INSERT INTO gtest20a (a) VALUES (30);
 ALTER TABLE gtest20a ADD CHECK (b < 50);  -- fails on existing row
 ERROR:  check constraint "gtest20a_b_check" of relation "gtest20a" is violated by some row
-CREATE TABLE gtest20b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE gtest20b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL);
 INSERT INTO gtest20b (a) VALUES (10);
 INSERT INTO gtest20b (a) VALUES (30);
 ALTER TABLE gtest20b ADD CONSTRAINT chk CHECK (b < 50) NOT VALID;
 ALTER TABLE gtest20b VALIDATE CONSTRAINT chk;  -- fails on existing row
 ERROR:  check constraint "chk" of relation "gtest20b" is violated by some row
 -- not-null constraints
-CREATE TABLE gtest21a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (nullif(a, 0)) STORED NOT NULL);
+CREATE TABLE gtest21a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (nullif(a, 0)) VIRTUAL NOT NULL);
 INSERT INTO gtest21a (a) VALUES (1);  -- ok
+ERROR:  null value in column "b" of relation "gtest21a" violates not-null constraint
+DETAIL:  Failing row contains (1).
 INSERT INTO gtest21a (a) VALUES (0);  -- violates constraint
 ERROR:  null value in column "b" of relation "gtest21a" violates not-null constraint
-DETAIL:  Failing row contains (0, null).
-CREATE TABLE gtest21b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (nullif(a, 0)) STORED);
-ALTER TABLE gtest21b ALTER COLUMN b SET NOT NULL;
+DETAIL:  Failing row contains (0).
+CREATE TABLE gtest21b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (nullif(a, 0)) VIRTUAL);
+ALTER TABLE gtest21b ALTER COLUMN b SET NOT NULL;  -- FIXME
 INSERT INTO gtest21b (a) VALUES (1);  -- ok
+ERROR:  null value in column "b" of relation "gtest21b" violates not-null constraint
+DETAIL:  Failing row contains (1).
 INSERT INTO gtest21b (a) VALUES (0);  -- violates constraint
 ERROR:  null value in column "b" of relation "gtest21b" violates not-null constraint
-DETAIL:  Failing row contains (0, null).
-ALTER TABLE gtest21b ALTER COLUMN b DROP NOT NULL;
+DETAIL:  Failing row contains (0).
+ALTER TABLE gtest21b ALTER COLUMN b DROP NOT NULL;  -- FIXME
 INSERT INTO gtest21b (a) VALUES (0);  -- ok now
 -- index constraints
-CREATE TABLE gtest22a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a / 2) STORED UNIQUE);
-INSERT INTO gtest22a VALUES (2);
-INSERT INTO gtest22a VALUES (3);
-ERROR:  duplicate key value violates unique constraint "gtest22a_b_key"
-DETAIL:  Key (b)=(1) already exists.
-INSERT INTO gtest22a VALUES (4);
-CREATE TABLE gtest22b (a int, b int GENERATED ALWAYS AS (a / 2) STORED, PRIMARY KEY (a, b));
-INSERT INTO gtest22b VALUES (2);
-INSERT INTO gtest22b VALUES (2);
-ERROR:  duplicate key value violates unique constraint "gtest22b_pkey"
-DETAIL:  Key (a, b)=(2, 1) already exists.
+CREATE TABLE gtest22a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a / 2) VIRTUAL UNIQUE);
+ERROR:  index creation on virtual generated columns is not supported
+--INSERT INTO gtest22a VALUES (2);
+--INSERT INTO gtest22a VALUES (3);
+--INSERT INTO gtest22a VALUES (4);
+CREATE TABLE gtest22b (a int, b int GENERATED ALWAYS AS (a / 2) VIRTUAL, PRIMARY KEY (a, b));
+ERROR:  index creation on virtual generated columns is not supported
+--INSERT INTO gtest22b VALUES (2);
+--INSERT INTO gtest22b VALUES (2);
 -- indexes
-CREATE TABLE gtest22c (a int, b int GENERATED ALWAYS AS (a * 2) STORED);
-CREATE INDEX gtest22c_b_idx ON gtest22c (b);
-CREATE INDEX gtest22c_expr_idx ON gtest22c ((b * 3));
-CREATE INDEX gtest22c_pred_idx ON gtest22c (a) WHERE b > 0;
-\d gtest22c
-                   Table "generated_stored_tests.gtest22c"
- Column |  Type   | Collation | Nullable |              Default               
---------+---------+-----------+----------+------------------------------------
- a      | integer |           |          | 
- b      | integer |           |          | generated always as (a * 2) stored
-Indexes:
-    "gtest22c_b_idx" btree (b)
-    "gtest22c_expr_idx" btree ((b * 3))
-    "gtest22c_pred_idx" btree (a) WHERE b > 0
-
-INSERT INTO gtest22c VALUES (1), (2), (3);
-SET enable_seqscan TO off;
-SET enable_bitmapscan TO off;
-EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b = 4;
-                 QUERY PLAN                  
----------------------------------------------
- Index Scan using gtest22c_b_idx on gtest22c
-   Index Cond: (b = 4)
-(2 rows)
-
-SELECT * FROM gtest22c WHERE b = 4;
- a | b 
----+---
- 2 | 4
-(1 row)
-
-EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b * 3 = 6;
-                   QUERY PLAN                   
-------------------------------------------------
- Index Scan using gtest22c_expr_idx on gtest22c
-   Index Cond: ((b * 3) = 6)
-(2 rows)
-
-SELECT * FROM gtest22c WHERE b * 3 = 6;
- a | b 
----+---
- 1 | 2
-(1 row)
-
-EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
-                   QUERY PLAN                   
-------------------------------------------------
- Index Scan using gtest22c_pred_idx on gtest22c
-   Index Cond: (a = 1)
-(2 rows)
-
-SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
- a | b 
----+---
- 1 | 2
-(1 row)
-
-ALTER TABLE gtest22c ALTER COLUMN b SET EXPRESSION AS (a * 4);
-ANALYZE gtest22c;
-EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b = 8;
-                 QUERY PLAN                  
----------------------------------------------
- Index Scan using gtest22c_b_idx on gtest22c
-   Index Cond: (b = 8)
-(2 rows)
-
-SELECT * FROM gtest22c WHERE b = 8;
- a | b 
----+---
- 2 | 8
-(1 row)
-
-EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b * 3 = 12;
-                   QUERY PLAN                   
-------------------------------------------------
- Index Scan using gtest22c_expr_idx on gtest22c
-   Index Cond: ((b * 3) = 12)
-(2 rows)
-
-SELECT * FROM gtest22c WHERE b * 3 = 12;
- a | b 
----+---
- 1 | 4
-(1 row)
-
-EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
-                   QUERY PLAN                   
-------------------------------------------------
- Index Scan using gtest22c_pred_idx on gtest22c
-   Index Cond: (a = 1)
-(2 rows)
-
-SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
- a | b 
----+---
- 1 | 4
-(1 row)
-
-RESET enable_seqscan;
-RESET enable_bitmapscan;
+CREATE TABLE gtest22c (a int, b int GENERATED ALWAYS AS (a * 2) VIRTUAL);
+--CREATE INDEX gtest22c_b_idx ON gtest22c (b);
+--CREATE INDEX gtest22c_expr_idx ON gtest22c ((b * 3));
+--CREATE INDEX gtest22c_pred_idx ON gtest22c (a) WHERE b > 0;
+--\d gtest22c
+--INSERT INTO gtest22c VALUES (1), (2), (3);
+--SET enable_seqscan TO off;
+--SET enable_bitmapscan TO off;
+--EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b = 4;
+--SELECT * FROM gtest22c WHERE b = 4;
+--EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b * 3 = 6;
+--SELECT * FROM gtest22c WHERE b * 3 = 6;
+--EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
+--SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
+--ALTER TABLE gtest22c ALTER COLUMN b SET EXPRESSION AS (a * 4);
+--ANALYZE gtest22c;
+--EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b = 8;
+--SELECT * FROM gtest22c WHERE b = 8;
+--EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b * 3 = 12;
+--SELECT * FROM gtest22c WHERE b * 3 = 12;
+--EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
+--SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
+--RESET enable_seqscan;
+--RESET enable_bitmapscan;
 -- foreign keys
 CREATE TABLE gtest23a (x int PRIMARY KEY, y int);
-INSERT INTO gtest23a VALUES (1, 11), (2, 22), (3, 33);
-CREATE TABLE gtest23x (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED REFERENCES gtest23a (x) ON UPDATE CASCADE);  -- error
+--INSERT INTO gtest23a VALUES (1, 11), (2, 22), (3, 33);
+CREATE TABLE gtest23x (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL REFERENCES gtest23a (x) ON UPDATE CASCADE);  -- error
 ERROR:  invalid ON UPDATE action for foreign key constraint containing generated column
-CREATE TABLE gtest23x (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED REFERENCES gtest23a (x) ON DELETE SET NULL);  -- error
+CREATE TABLE gtest23x (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL REFERENCES gtest23a (x) ON DELETE SET NULL);  -- error
 ERROR:  invalid ON DELETE action for foreign key constraint containing generated column
-CREATE TABLE gtest23b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED REFERENCES gtest23a (x));
-\d gtest23b
-                   Table "generated_stored_tests.gtest23b"
- Column |  Type   | Collation | Nullable |              Default               
---------+---------+-----------+----------+------------------------------------
- a      | integer |           | not null | 
- b      | integer |           |          | generated always as (a * 2) stored
-Indexes:
-    "gtest23b_pkey" PRIMARY KEY, btree (a)
-Foreign-key constraints:
-    "gtest23b_b_fkey" FOREIGN KEY (b) REFERENCES gtest23a(x)
-
-INSERT INTO gtest23b VALUES (1);  -- ok
-INSERT INTO gtest23b VALUES (5);  -- error
-ERROR:  insert or update on table "gtest23b" violates foreign key constraint "gtest23b_b_fkey"
-DETAIL:  Key (b)=(10) is not present in table "gtest23a".
-ALTER TABLE gtest23b ALTER COLUMN b SET EXPRESSION AS (a * 5); -- error
-ERROR:  insert or update on table "gtest23b" violates foreign key constraint "gtest23b_b_fkey"
-DETAIL:  Key (b)=(5) is not present in table "gtest23a".
-ALTER TABLE gtest23b ALTER COLUMN b SET EXPRESSION AS (a * 1); -- ok
-DROP TABLE gtest23b;
-DROP TABLE gtest23a;
-CREATE TABLE gtest23p (x int, y int GENERATED ALWAYS AS (x * 2) STORED, PRIMARY KEY (y));
-INSERT INTO gtest23p VALUES (1), (2), (3);
+CREATE TABLE gtest23b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL REFERENCES gtest23a (x));
+ERROR:  foreign key constraints on virtual generated columns are not supported
+--\d gtest23b
+--INSERT INTO gtest23b VALUES (1);  -- ok
+--INSERT INTO gtest23b VALUES (5);  -- error
+--ALTER TABLE gtest23b ALTER COLUMN b SET EXPRESSION AS (a * 5); -- error
+--ALTER TABLE gtest23b ALTER COLUMN b SET EXPRESSION AS (a * 1); -- ok
+--DROP TABLE gtest23b;
+--DROP TABLE gtest23a;
+CREATE TABLE gtest23p (x int, y int GENERATED ALWAYS AS (x * 2) VIRTUAL, PRIMARY KEY (y));
+ERROR:  index creation on virtual generated columns is not supported
+--INSERT INTO gtest23p VALUES (1), (2), (3);
 CREATE TABLE gtest23q (a int PRIMARY KEY, b int REFERENCES gtest23p (y));
-INSERT INTO gtest23q VALUES (1, 2);  -- ok
-INSERT INTO gtest23q VALUES (2, 5);  -- error
-ERROR:  insert or update on table "gtest23q" violates foreign key constraint "gtest23q_b_fkey"
-DETAIL:  Key (b)=(5) is not present in table "gtest23p".
+ERROR:  relation "gtest23p" does not exist
+--INSERT INTO gtest23q VALUES (1, 2);  -- ok
+--INSERT INTO gtest23q VALUES (2, 5);  -- error
 -- domains
 CREATE DOMAIN gtestdomain1 AS int CHECK (VALUE < 10);
-CREATE TABLE gtest24 (a int PRIMARY KEY, b gtestdomain1 GENERATED ALWAYS AS (a * 2) STORED);
-INSERT INTO gtest24 (a) VALUES (4);  -- ok
-INSERT INTO gtest24 (a) VALUES (6);  -- error
-ERROR:  value for domain gtestdomain1 violates check constraint "gtestdomain1_check"
+CREATE TABLE gtest24 (a int PRIMARY KEY, b gtestdomain1 GENERATED ALWAYS AS (a * 2) VIRTUAL);
+--INSERT INTO gtest24 (a) VALUES (4);  -- ok
+--INSERT INTO gtest24 (a) VALUES (6);  -- error
 -- typed tables (currently not supported)
 CREATE TYPE gtest_type AS (f1 integer, f2 text, f3 bigint);
-CREATE TABLE gtest28 OF gtest_type (f1 WITH OPTIONS GENERATED ALWAYS AS (f2 *2) STORED);
+CREATE TABLE gtest28 OF gtest_type (f1 WITH OPTIONS GENERATED ALWAYS AS (f2 *2) VIRTUAL);
 ERROR:  generated columns are not supported on typed tables
 DROP TYPE gtest_type CASCADE;
 -- partitioning cases
 CREATE TABLE gtest_parent (f1 date NOT NULL, f2 bigint, f3 bigint) PARTITION BY RANGE (f1);
 CREATE TABLE gtest_child PARTITION OF gtest_parent (
-    f3 WITH OPTIONS GENERATED ALWAYS AS (f2 * 2) STORED
+    f3 WITH OPTIONS GENERATED ALWAYS AS (f2 * 2) VIRTUAL
 ) FOR VALUES FROM ('2016-07-01') TO ('2016-08-01'); -- error
 ERROR:  child column "f3" specifies generation expression
 HINT:  A child table column cannot be generated unless its parent column is.
-CREATE TABLE gtest_child (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) STORED);
+CREATE TABLE gtest_child (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) VIRTUAL);
 ALTER TABLE gtest_parent ATTACH PARTITION gtest_child FOR VALUES FROM ('2016-07-01') TO ('2016-08-01'); -- error
 ERROR:  column "f3" in child table must not be a generated column
 DROP TABLE gtest_parent, gtest_child;
-CREATE TABLE gtest_parent (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE (f1);
+CREATE TABLE gtest_parent (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) VIRTUAL) PARTITION BY RANGE (f1);
 CREATE TABLE gtest_child PARTITION OF gtest_parent
   FOR VALUES FROM ('2016-07-01') TO ('2016-08-01');  -- inherits gen expr
 CREATE TABLE gtest_child2 PARTITION OF gtest_parent (
-    f3 WITH OPTIONS GENERATED ALWAYS AS (f2 * 22) STORED  -- overrides gen expr
+    f3 WITH OPTIONS GENERATED ALWAYS AS (f2 * 22) VIRTUAL  -- overrides gen expr
 ) FOR VALUES FROM ('2016-08-01') TO ('2016-09-01');
 CREATE TABLE gtest_child3 PARTITION OF gtest_parent (
     f3 DEFAULT 42  -- error
@@ -807,33 +710,33 @@ ALTER TABLE gtest_parent ATTACH PARTITION gtest_child3 FOR VALUES FROM ('2016-09
 ERROR:  table "gtest_child3" being attached contains an identity column "f3"
 DETAIL:  The new partition may not contain an identity column.
 DROP TABLE gtest_child3;
-CREATE TABLE gtest_child3 (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 33) STORED);
+CREATE TABLE gtest_child3 (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 33) VIRTUAL);
 ALTER TABLE gtest_parent ATTACH PARTITION gtest_child3 FOR VALUES FROM ('2016-09-01') TO ('2016-10-01');
 \d gtest_child
-                  Table "generated_stored_tests.gtest_child"
- Column |  Type  | Collation | Nullable |               Default               
---------+--------+-----------+----------+-------------------------------------
+              Table "generated_virtual_tests.gtest_child"
+ Column |  Type  | Collation | Nullable |           Default            
+--------+--------+-----------+----------+------------------------------
  f1     | date   |           | not null | 
  f2     | bigint |           |          | 
- f3     | bigint |           |          | generated always as (f2 * 2) stored
+ f3     | bigint |           |          | generated always as (f2 * 2)
 Partition of: gtest_parent FOR VALUES FROM ('07-01-2016') TO ('08-01-2016')
 
 \d gtest_child2
-                  Table "generated_stored_tests.gtest_child2"
- Column |  Type  | Collation | Nullable |               Default                
---------+--------+-----------+----------+--------------------------------------
+              Table "generated_virtual_tests.gtest_child2"
+ Column |  Type  | Collation | Nullable |            Default            
+--------+--------+-----------+----------+-------------------------------
  f1     | date   |           | not null | 
  f2     | bigint |           |          | 
- f3     | bigint |           |          | generated always as (f2 * 22) stored
+ f3     | bigint |           |          | generated always as (f2 * 22)
 Partition of: gtest_parent FOR VALUES FROM ('08-01-2016') TO ('09-01-2016')
 
 \d gtest_child3
-                  Table "generated_stored_tests.gtest_child3"
- Column |  Type  | Collation | Nullable |               Default                
---------+--------+-----------+----------+--------------------------------------
+              Table "generated_virtual_tests.gtest_child3"
+ Column |  Type  | Collation | Nullable |            Default            
+--------+--------+-----------+----------+-------------------------------
  f1     | date   |           | not null | 
  f2     | bigint |           |          | 
- f3     | bigint |           |          | generated always as (f2 * 33) stored
+ f3     | bigint |           |          | generated always as (f2 * 33)
 Partition of: gtest_parent FOR VALUES FROM ('09-01-2016') TO ('10-01-2016')
 
 INSERT INTO gtest_parent (f1, f2) VALUES ('2016-07-15', 1);
@@ -844,7 +747,7 @@ SELECT tableoid::regclass, * FROM gtest_parent ORDER BY 1, 2, 3;
 --------------+------------+----+----
  gtest_child  | 07-15-2016 |  1 |  2
  gtest_child  | 07-15-2016 |  2 |  4
- gtest_child2 | 08-15-2016 |  3 | 66
+ gtest_child2 | 08-15-2016 |  3 |  6
 (3 rows)
 
 UPDATE gtest_parent SET f1 = f1 + 60 WHERE f2 = 1;
@@ -852,95 +755,98 @@ SELECT tableoid::regclass, * FROM gtest_parent ORDER BY 1, 2, 3;
    tableoid   |     f1     | f2 | f3 
 --------------+------------+----+----
  gtest_child  | 07-15-2016 |  2 |  4
- gtest_child2 | 08-15-2016 |  3 | 66
- gtest_child3 | 09-13-2016 |  1 | 33
+ gtest_child2 | 08-15-2016 |  3 |  6
+ gtest_child3 | 09-13-2016 |  1 |  2
 (3 rows)
 
 -- alter only parent's and one child's generation expression
 ALTER TABLE ONLY gtest_parent ALTER COLUMN f3 SET EXPRESSION AS (f2 * 4);
+ERROR:  column "f3" of relation "gtest_parent" is not a generated column
 ALTER TABLE gtest_child ALTER COLUMN f3 SET EXPRESSION AS (f2 * 10);
+ERROR:  column "f3" of relation "gtest_child" is not a generated column
 \d gtest_parent
-           Partitioned table "generated_stored_tests.gtest_parent"
- Column |  Type  | Collation | Nullable |               Default               
---------+--------+-----------+----------+-------------------------------------
+       Partitioned table "generated_virtual_tests.gtest_parent"
+ Column |  Type  | Collation | Nullable |           Default            
+--------+--------+-----------+----------+------------------------------
  f1     | date   |           | not null | 
  f2     | bigint |           |          | 
- f3     | bigint |           |          | generated always as (f2 * 4) stored
+ f3     | bigint |           |          | generated always as (f2 * 2)
 Partition key: RANGE (f1)
 Number of partitions: 3 (Use \d+ to list them.)
 
 \d gtest_child
-                  Table "generated_stored_tests.gtest_child"
- Column |  Type  | Collation | Nullable |               Default                
---------+--------+-----------+----------+--------------------------------------
+              Table "generated_virtual_tests.gtest_child"
+ Column |  Type  | Collation | Nullable |           Default            
+--------+--------+-----------+----------+------------------------------
  f1     | date   |           | not null | 
  f2     | bigint |           |          | 
- f3     | bigint |           |          | generated always as (f2 * 10) stored
+ f3     | bigint |           |          | generated always as (f2 * 2)
 Partition of: gtest_parent FOR VALUES FROM ('07-01-2016') TO ('08-01-2016')
 
 \d gtest_child2
-                  Table "generated_stored_tests.gtest_child2"
- Column |  Type  | Collation | Nullable |               Default                
---------+--------+-----------+----------+--------------------------------------
+              Table "generated_virtual_tests.gtest_child2"
+ Column |  Type  | Collation | Nullable |            Default            
+--------+--------+-----------+----------+-------------------------------
  f1     | date   |           | not null | 
  f2     | bigint |           |          | 
- f3     | bigint |           |          | generated always as (f2 * 22) stored
+ f3     | bigint |           |          | generated always as (f2 * 22)
 Partition of: gtest_parent FOR VALUES FROM ('08-01-2016') TO ('09-01-2016')
 
 \d gtest_child3
-                  Table "generated_stored_tests.gtest_child3"
- Column |  Type  | Collation | Nullable |               Default                
---------+--------+-----------+----------+--------------------------------------
+              Table "generated_virtual_tests.gtest_child3"
+ Column |  Type  | Collation | Nullable |            Default            
+--------+--------+-----------+----------+-------------------------------
  f1     | date   |           | not null | 
  f2     | bigint |           |          | 
- f3     | bigint |           |          | generated always as (f2 * 33) stored
+ f3     | bigint |           |          | generated always as (f2 * 33)
 Partition of: gtest_parent FOR VALUES FROM ('09-01-2016') TO ('10-01-2016')
 
 SELECT tableoid::regclass, * FROM gtest_parent ORDER BY 1, 2, 3;
    tableoid   |     f1     | f2 | f3 
 --------------+------------+----+----
- gtest_child  | 07-15-2016 |  2 | 20
- gtest_child2 | 08-15-2016 |  3 | 66
- gtest_child3 | 09-13-2016 |  1 | 33
+ gtest_child  | 07-15-2016 |  2 |  4
+ gtest_child2 | 08-15-2016 |  3 |  6
+ gtest_child3 | 09-13-2016 |  1 |  2
 (3 rows)
 
 -- alter generation expression of parent and all its children altogether
 ALTER TABLE gtest_parent ALTER COLUMN f3 SET EXPRESSION AS (f2 * 2);
+ERROR:  column "f3" of relation "gtest_parent" is not a generated column
 \d gtest_parent
-           Partitioned table "generated_stored_tests.gtest_parent"
- Column |  Type  | Collation | Nullable |               Default               
---------+--------+-----------+----------+-------------------------------------
+       Partitioned table "generated_virtual_tests.gtest_parent"
+ Column |  Type  | Collation | Nullable |           Default            
+--------+--------+-----------+----------+------------------------------
  f1     | date   |           | not null | 
  f2     | bigint |           |          | 
- f3     | bigint |           |          | generated always as (f2 * 2) stored
+ f3     | bigint |           |          | generated always as (f2 * 2)
 Partition key: RANGE (f1)
 Number of partitions: 3 (Use \d+ to list them.)
 
 \d gtest_child
-                  Table "generated_stored_tests.gtest_child"
- Column |  Type  | Collation | Nullable |               Default               
---------+--------+-----------+----------+-------------------------------------
+              Table "generated_virtual_tests.gtest_child"
+ Column |  Type  | Collation | Nullable |           Default            
+--------+--------+-----------+----------+------------------------------
  f1     | date   |           | not null | 
  f2     | bigint |           |          | 
- f3     | bigint |           |          | generated always as (f2 * 2) stored
+ f3     | bigint |           |          | generated always as (f2 * 2)
 Partition of: gtest_parent FOR VALUES FROM ('07-01-2016') TO ('08-01-2016')
 
 \d gtest_child2
-                 Table "generated_stored_tests.gtest_child2"
- Column |  Type  | Collation | Nullable |               Default               
---------+--------+-----------+----------+-------------------------------------
+              Table "generated_virtual_tests.gtest_child2"
+ Column |  Type  | Collation | Nullable |            Default            
+--------+--------+-----------+----------+-------------------------------
  f1     | date   |           | not null | 
  f2     | bigint |           |          | 
- f3     | bigint |           |          | generated always as (f2 * 2) stored
+ f3     | bigint |           |          | generated always as (f2 * 22)
 Partition of: gtest_parent FOR VALUES FROM ('08-01-2016') TO ('09-01-2016')
 
 \d gtest_child3
-                 Table "generated_stored_tests.gtest_child3"
- Column |  Type  | Collation | Nullable |               Default               
---------+--------+-----------+----------+-------------------------------------
+              Table "generated_virtual_tests.gtest_child3"
+ Column |  Type  | Collation | Nullable |            Default            
+--------+--------+-----------+----------+-------------------------------
  f1     | date   |           | not null | 
  f2     | bigint |           |          | 
- f3     | bigint |           |          | generated always as (f2 * 2) stored
+ f3     | bigint |           |          | generated always as (f2 * 33)
 Partition of: gtest_parent FOR VALUES FROM ('09-01-2016') TO ('10-01-2016')
 
 SELECT tableoid::regclass, * FROM gtest_parent ORDER BY 1, 2, 3;
@@ -953,54 +859,53 @@ SELECT tableoid::regclass, * FROM gtest_parent ORDER BY 1, 2, 3;
 
 -- we leave these tables around for purposes of testing dump/reload/upgrade
 -- generated columns in partition key (not allowed)
-CREATE TABLE gtest_part_key (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE (f3);
+CREATE TABLE gtest_part_key (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) VIRTUAL) PARTITION BY RANGE (f3);
 ERROR:  cannot use generated column in partition key
-LINE 1: ...ENERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE (f3);
+LINE 1: ...NERATED ALWAYS AS (f2 * 2) VIRTUAL) PARTITION BY RANGE (f3);
                                                                    ^
 DETAIL:  Column "f3" is a generated column.
-CREATE TABLE gtest_part_key (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE ((f3 * 3));
+CREATE TABLE gtest_part_key (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) VIRTUAL) PARTITION BY RANGE ((f3 * 3));
 ERROR:  cannot use generated column in partition key
-LINE 1: ...ED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE ((f3 * 3));
+LINE 1: ...D ALWAYS AS (f2 * 2) VIRTUAL) PARTITION BY RANGE ((f3 * 3));
                                                              ^
 DETAIL:  Column "f3" is a generated column.
 -- ALTER TABLE ... ADD COLUMN
 CREATE TABLE gtest25 (a int PRIMARY KEY);
 INSERT INTO gtest25 VALUES (3), (4);
-ALTER TABLE gtest25 ADD COLUMN b int GENERATED ALWAYS AS (a * 2) STORED, ALTER COLUMN b SET EXPRESSION AS (a * 3);
+ALTER TABLE gtest25 ADD COLUMN b int GENERATED ALWAYS AS (a * 2) VIRTUAL, ALTER COLUMN b SET EXPRESSION AS (a * 3);
+ERROR:  column "b" of relation "gtest25" is not a generated column
 SELECT * FROM gtest25 ORDER BY a;
- a | b  
----+----
- 3 |  9
- 4 | 12
+ a 
+---
+ 3
+ 4
 (2 rows)
 
-ALTER TABLE gtest25 ADD COLUMN x int GENERATED ALWAYS AS (b * 4) STORED;  -- error
-ERROR:  cannot use generated column "b" in column generation expression
-DETAIL:  A generated column cannot reference another generated column.
-ALTER TABLE gtest25 ADD COLUMN x int GENERATED ALWAYS AS (z * 4) STORED;  -- error
+ALTER TABLE gtest25 ADD COLUMN x int GENERATED ALWAYS AS (b * 4) VIRTUAL;  -- error
+ERROR:  column "b" does not exist
+ALTER TABLE gtest25 ADD COLUMN x int GENERATED ALWAYS AS (z * 4) VIRTUAL;  -- error
 ERROR:  column "z" does not exist
 ALTER TABLE gtest25 ADD COLUMN c int DEFAULT 42,
-  ADD COLUMN x int GENERATED ALWAYS AS (c * 4) STORED;
+  ADD COLUMN x int GENERATED ALWAYS AS (c * 4) VIRTUAL;
 ALTER TABLE gtest25 ADD COLUMN d int DEFAULT 101;
 ALTER TABLE gtest25 ALTER COLUMN d SET DATA TYPE float8,
-  ADD COLUMN y float8 GENERATED ALWAYS AS (d * 4) STORED;
+  ADD COLUMN y float8 GENERATED ALWAYS AS (d * 4) VIRTUAL;
 SELECT * FROM gtest25 ORDER BY a;
- a | b  | c  |  x  |  d  |  y  
----+----+----+-----+-----+-----
- 3 |  9 | 42 | 168 | 101 | 404
- 4 | 12 | 42 | 168 | 101 | 404
+ a | c  |  x  |  d  |  y  
+---+----+-----+-----+-----
+ 3 | 42 | 168 | 101 | 404
+ 4 | 42 | 168 | 101 | 404
 (2 rows)
 
 \d gtest25
-                                 Table "generated_stored_tests.gtest25"
- Column |       Type       | Collation | Nullable |                       Default                        
---------+------------------+-----------+----------+------------------------------------------------------
+                             Table "generated_virtual_tests.gtest25"
+ Column |       Type       | Collation | Nullable |                    Default                    
+--------+------------------+-----------+----------+-----------------------------------------------
  a      | integer          |           | not null | 
- b      | integer          |           |          | generated always as (a * 3) stored
  c      | integer          |           |          | 42
- x      | integer          |           |          | generated always as (c * 4) stored
+ x      | integer          |           |          | generated always as (c * 4)
  d      | double precision |           |          | 101
- y      | double precision |           |          | generated always as (d * 4::double precision) stored
+ y      | double precision |           |          | generated always as (d * 4::double precision)
 Indexes:
     "gtest25_pkey" PRIMARY KEY, btree (a)
 
@@ -1008,7 +913,7 @@ Indexes:
 CREATE TABLE gtest27 (
     a int,
     b int,
-    x int GENERATED ALWAYS AS ((a + b) * 2) STORED
+    x int GENERATED ALWAYS AS ((a + b) * 2) VIRTUAL
 );
 INSERT INTO gtest27 (a, b) VALUES (3, 7), (4, 11);
 ALTER TABLE gtest27 ALTER COLUMN a TYPE text;  -- error
@@ -1016,12 +921,12 @@ ERROR:  cannot alter type of a column used by a generated column
 DETAIL:  Column "a" is used by generated column "x".
 ALTER TABLE gtest27 ALTER COLUMN x TYPE numeric;
 \d gtest27
-                        Table "generated_stored_tests.gtest27"
- Column |  Type   | Collation | Nullable |                  Default                   
---------+---------+-----------+----------+--------------------------------------------
+                    Table "generated_virtual_tests.gtest27"
+ Column |  Type   | Collation | Nullable |               Default               
+--------+---------+-----------+----------+-------------------------------------
  a      | integer |           |          | 
  b      | integer |           |          | 
- x      | numeric |           |          | generated always as (((a + b) * 2)) stored
+ x      | numeric |           |          | generated always as (((a + b) * 2))
 
 SELECT * FROM gtest27;
  a | b  | x  
@@ -1034,20 +939,19 @@ ALTER TABLE gtest27 ALTER COLUMN x TYPE boolean USING x <> 0;  -- error
 ERROR:  generation expression for column "x" cannot be cast automatically to type boolean
 ALTER TABLE gtest27 ALTER COLUMN x DROP DEFAULT;  -- error
 ERROR:  column "x" of relation "gtest27" is a generated column
-HINT:  Use ALTER TABLE ... ALTER COLUMN ... DROP EXPRESSION instead.
 -- It's possible to alter the column types this way:
 ALTER TABLE gtest27
   DROP COLUMN x,
   ALTER COLUMN a TYPE bigint,
   ALTER COLUMN b TYPE bigint,
-  ADD COLUMN x bigint GENERATED ALWAYS AS ((a + b) * 2) STORED;
+  ADD COLUMN x bigint GENERATED ALWAYS AS ((a + b) * 2) VIRTUAL;
 \d gtest27
-                      Table "generated_stored_tests.gtest27"
- Column |  Type  | Collation | Nullable |                 Default                  
---------+--------+-----------+----------+------------------------------------------
+                  Table "generated_virtual_tests.gtest27"
+ Column |  Type  | Collation | Nullable |              Default              
+--------+--------+-----------+----------+-----------------------------------
  a      | bigint |           |          | 
  b      | bigint |           |          | 
- x      | bigint |           |          | generated always as ((a + b) * 2) stored
+ x      | bigint |           |          | generated always as ((a + b) * 2)
 
 -- Ideally you could just do this, but not today (and should x change type?):
 ALTER TABLE gtest27
@@ -1056,12 +960,12 @@ ALTER TABLE gtest27
 ERROR:  cannot alter type of a column used by a generated column
 DETAIL:  Column "a" is used by generated column "x".
 \d gtest27
-                      Table "generated_stored_tests.gtest27"
- Column |  Type  | Collation | Nullable |                 Default                  
---------+--------+-----------+----------+------------------------------------------
+                  Table "generated_virtual_tests.gtest27"
+ Column |  Type  | Collation | Nullable |              Default              
+--------+--------+-----------+----------+-----------------------------------
  a      | bigint |           |          | 
  b      | bigint |           |          | 
- x      | bigint |           |          | generated always as ((a + b) * 2) stored
+ x      | bigint |           |          | generated always as ((a + b) * 2)
 
 SELECT * FROM gtest27;
  a | b  | x  
@@ -1073,7 +977,7 @@ SELECT * FROM gtest27;
 -- ALTER TABLE ... ALTER COLUMN ... DROP EXPRESSION
 CREATE TABLE gtest29 (
     a int,
-    b int GENERATED ALWAYS AS (a * 2) STORED
+    b int GENERATED ALWAYS AS (a * 2) VIRTUAL
 );
 INSERT INTO gtest29 (a) VALUES (3), (4);
 SELECT * FROM gtest29;
@@ -1084,11 +988,11 @@ SELECT * FROM gtest29;
 (2 rows)
 
 \d gtest29
-                    Table "generated_stored_tests.gtest29"
- Column |  Type   | Collation | Nullable |              Default               
---------+---------+-----------+----------+------------------------------------
+                Table "generated_virtual_tests.gtest29"
+ Column |  Type   | Collation | Nullable |           Default           
+--------+---------+-----------+----------+-----------------------------
  a      | integer |           |          | 
- b      | integer |           |          | generated always as (a * 2) stored
+ b      | integer |           |          | generated always as (a * 2)
 
 ALTER TABLE gtest29 ALTER COLUMN a SET EXPRESSION AS (a * 3);  -- error
 ERROR:  column "a" of relation "gtest29" is not a generated column
@@ -1098,93 +1002,101 @@ ALTER TABLE gtest29 ALTER COLUMN a DROP EXPRESSION IF EXISTS;  -- notice
 NOTICE:  column "a" of relation "gtest29" is not a stored generated column, skipping
 -- Change the expression
 ALTER TABLE gtest29 ALTER COLUMN b SET EXPRESSION AS (a * 3);
+ERROR:  column "b" of relation "gtest29" is not a generated column
 SELECT * FROM gtest29;
- a | b  
----+----
- 3 |  9
- 4 | 12
+ a | b 
+---+---
+ 3 | 6
+ 4 | 8
 (2 rows)
 
 \d gtest29
-                    Table "generated_stored_tests.gtest29"
- Column |  Type   | Collation | Nullable |              Default               
---------+---------+-----------+----------+------------------------------------
+                Table "generated_virtual_tests.gtest29"
+ Column |  Type   | Collation | Nullable |           Default           
+--------+---------+-----------+----------+-----------------------------
  a      | integer |           |          | 
- b      | integer |           |          | generated always as (a * 3) stored
+ b      | integer |           |          | generated always as (a * 2)
 
 ALTER TABLE gtest29 ALTER COLUMN b DROP EXPRESSION;
+ERROR:  column "b" of relation "gtest29" is not a stored generated column
 INSERT INTO gtest29 (a) VALUES (5);
 INSERT INTO gtest29 (a, b) VALUES (6, 66);
+ERROR:  cannot insert a non-DEFAULT value into column "b"
+DETAIL:  Column "b" is a generated column.
 SELECT * FROM gtest29;
  a | b  
 ---+----
- 3 |  9
- 4 | 12
- 5 |   
- 6 | 66
-(4 rows)
+ 3 |  6
+ 4 |  8
+ 5 | 10
+(3 rows)
 
 \d gtest29
-      Table "generated_stored_tests.gtest29"
- Column |  Type   | Collation | Nullable | Default 
---------+---------+-----------+----------+---------
+                Table "generated_virtual_tests.gtest29"
+ Column |  Type   | Collation | Nullable |           Default           
+--------+---------+-----------+----------+-----------------------------
  a      | integer |           |          | 
- b      | integer |           |          | 
+ b      | integer |           |          | generated always as (a * 2)
 
 -- check that dependencies between columns have also been removed
 ALTER TABLE gtest29 DROP COLUMN a;  -- should not drop b
+ERROR:  cannot drop column a of table gtest29 because other objects depend on it
+DETAIL:  column b of table gtest29 depends on column a of table gtest29
+HINT:  Use DROP ... CASCADE to drop the dependent objects too.
 \d gtest29
-      Table "generated_stored_tests.gtest29"
- Column |  Type   | Collation | Nullable | Default 
---------+---------+-----------+----------+---------
- b      | integer |           |          | 
+                Table "generated_virtual_tests.gtest29"
+ Column |  Type   | Collation | Nullable |           Default           
+--------+---------+-----------+----------+-----------------------------
+ a      | integer |           |          | 
+ b      | integer |           |          | generated always as (a * 2)
 
 -- with inheritance
 CREATE TABLE gtest30 (
     a int,
-    b int GENERATED ALWAYS AS (a * 2) STORED
+    b int GENERATED ALWAYS AS (a * 2) VIRTUAL
 );
 CREATE TABLE gtest30_1 () INHERITS (gtest30);
 ALTER TABLE gtest30 ALTER COLUMN b DROP EXPRESSION;
+ERROR:  column "b" of relation "gtest30" is not a stored generated column
 \d gtest30
-      Table "generated_stored_tests.gtest30"
- Column |  Type   | Collation | Nullable | Default 
---------+---------+-----------+----------+---------
+                Table "generated_virtual_tests.gtest30"
+ Column |  Type   | Collation | Nullable |           Default           
+--------+---------+-----------+----------+-----------------------------
  a      | integer |           |          | 
- b      | integer |           |          | 
+ b      | integer |           |          | generated always as (a * 2)
 Number of child tables: 1 (Use \d+ to list them.)
 
 \d gtest30_1
-     Table "generated_stored_tests.gtest30_1"
- Column |  Type   | Collation | Nullable | Default 
---------+---------+-----------+----------+---------
+               Table "generated_virtual_tests.gtest30_1"
+ Column |  Type   | Collation | Nullable |           Default           
+--------+---------+-----------+----------+-----------------------------
  a      | integer |           |          | 
- b      | integer |           |          | 
+ b      | integer |           |          | generated always as (a * 2)
 Inherits: gtest30
 
 DROP TABLE gtest30 CASCADE;
 NOTICE:  drop cascades to table gtest30_1
 CREATE TABLE gtest30 (
     a int,
-    b int GENERATED ALWAYS AS (a * 2) STORED
+    b int GENERATED ALWAYS AS (a * 2) VIRTUAL
 );
 CREATE TABLE gtest30_1 () INHERITS (gtest30);
 ALTER TABLE ONLY gtest30 ALTER COLUMN b DROP EXPRESSION;  -- error
 ERROR:  ALTER TABLE / DROP EXPRESSION must be applied to child tables too
 \d gtest30
-                    Table "generated_stored_tests.gtest30"
- Column |  Type   | Collation | Nullable |              Default               
---------+---------+-----------+----------+------------------------------------
+                Table "generated_virtual_tests.gtest30"
+ Column |  Type   | Collation | Nullable |           Default           
+--------+---------+-----------+----------+-----------------------------
  a      | integer |           |          | 
- b      | integer |           |          | generated always as (a * 2) stored
+ b      | integer |           |          | generated always as (a * 2)
 Number of child tables: 1 (Use \d+ to list them.)
 
 \d gtest30_1
-                   Table "generated_stored_tests.gtest30_1"
- Column |  Type   | Collation | Nullable |              Default               
---------+---------+-----------+----------+------------------------------------
+               Table "generated_virtual_tests.gtest30_1"
+ Column |  Type   | Collation | Nullable |           Default           
+--------+---------+-----------+----------+-----------------------------
  a      | integer |           |          | 
- b      | integer |           |          | generated always as (a * 2) stored
+ b      | integer |           |          | generated always as (a * 2)
 Inherits: gtest30
 
 ALTER TABLE gtest30_1 ALTER COLUMN b DROP EXPRESSION;  -- error
@@ -1192,7 +1104,7 @@ ERROR:  cannot drop generation expression from inherited column
 -- triggers
 CREATE TABLE gtest26 (
     a int PRIMARY KEY,
-    b int GENERATED ALWAYS AS (a * 2) STORED
+    b int GENERATED ALWAYS AS (a * 2) VIRTUAL
 );
 CREATE FUNCTION gtest_trigger_func() RETURNS trigger
   LANGUAGE plpgsql
@@ -1245,7 +1157,7 @@ CREATE TRIGGER gtest4 AFTER INSERT OR UPDATE ON gtest26
   EXECUTE PROCEDURE gtest_trigger_func();
 INSERT INTO gtest26 (a) VALUES (-2), (0), (3);
 INFO:  gtest2: BEFORE: new = (-2,)
-INFO:  gtest4: AFTER: new = (-2,-4)
+INFO:  gtest4: AFTER: new = (-2,)
 SELECT * FROM gtest26 ORDER BY a;
  a  | b  
 ----+----
@@ -1255,12 +1167,12 @@ SELECT * FROM gtest26 ORDER BY a;
 (3 rows)
 
 UPDATE gtest26 SET a = a * -2;
-INFO:  gtest1: BEFORE: old = (-2,-4)
+INFO:  gtest1: BEFORE: old = (-2,)
 INFO:  gtest1: BEFORE: new = (4,)
-INFO:  gtest3: AFTER: old = (-2,-4)
-INFO:  gtest3: AFTER: new = (4,8)
-INFO:  gtest4: AFTER: old = (3,6)
-INFO:  gtest4: AFTER: new = (-6,-12)
+INFO:  gtest3: AFTER: old = (-2,)
+INFO:  gtest3: AFTER: new = (4,)
+INFO:  gtest4: AFTER: old = (3,)
+INFO:  gtest4: AFTER: new = (-6,)
 SELECT * FROM gtest26 ORDER BY a;
  a  |  b  
 ----+-----
@@ -1270,8 +1182,8 @@ SELECT * FROM gtest26 ORDER BY a;
 (3 rows)
 
 DELETE FROM gtest26 WHERE a = -6;
-INFO:  gtest1: BEFORE: old = (-6,-12)
-INFO:  gtest3: AFTER: old = (-6,-12)
+INFO:  gtest1: BEFORE: old = (-6,)
+INFO:  gtest3: AFTER: old = (-6,)
 SELECT * FROM gtest26 ORDER BY a;
  a | b 
 ---+---
@@ -1282,6 +1194,8 @@ SELECT * FROM gtest26 ORDER BY a;
 DROP TRIGGER gtest1 ON gtest26;
 DROP TRIGGER gtest2 ON gtest26;
 DROP TRIGGER gtest3 ON gtest26;
+-- check disallowed modification of virtual columns
+-- TODO
 -- Check that an UPDATE of "a" fires the trigger for UPDATE OF b, per
 -- SQL standard.
 CREATE FUNCTION gtest_trigger_func3() RETURNS trigger
@@ -1295,9 +1209,11 @@ $$;
 CREATE TRIGGER gtest11 BEFORE UPDATE OF b ON gtest26
   FOR EACH ROW
   EXECUTE PROCEDURE gtest_trigger_func3();
+ERROR:  virtual generated columns are not supported as trigger columns
+DETAIL:  Column "b" is a virtual generated column.
 UPDATE gtest26 SET a = 1 WHERE a = 0;
-NOTICE:  OK
 DROP TRIGGER gtest11 ON gtest26;
+ERROR:  trigger "gtest11" for table "gtest26" does not exist
 TRUNCATE gtest26;
 -- check that modifications of stored generated columns in triggers do
 -- not get propagated
@@ -1321,14 +1237,13 @@ CREATE TRIGGER gtest12_03 BEFORE UPDATE ON gtest26
   EXECUTE PROCEDURE gtest_trigger_func();
 INSERT INTO gtest26 (a) VALUES (1);
 UPDATE gtest26 SET a = 11 WHERE a = 1;
-INFO:  gtest12_01: BEFORE: old = (1,2)
+INFO:  gtest12_01: BEFORE: old = (1,)
 INFO:  gtest12_01: BEFORE: new = (11,)
-INFO:  gtest12_03: BEFORE: old = (1,2)
-INFO:  gtest12_03: BEFORE: new = (10,)
+ERROR:  trigger modified virtual generated column value
 SELECT * FROM gtest26 ORDER BY a;
- a  | b  
-----+----
- 10 | 20
+ a | b 
+---+---
+ 1 | 2
 (1 row)
 
 -- LIKE INCLUDING GENERATED and dropped column handling
@@ -1336,22 +1251,22 @@ CREATE TABLE gtest28a (
   a int,
   b int,
   c int,
-  x int GENERATED ALWAYS AS (b * 2) STORED
+  x int GENERATED ALWAYS AS (b * 2) VIRTUAL
 );
 ALTER TABLE gtest28a DROP COLUMN a;
 CREATE TABLE gtest28b (LIKE gtest28a INCLUDING GENERATED);
 \d gtest28*
-                   Table "generated_stored_tests.gtest28a"
- Column |  Type   | Collation | Nullable |              Default               
---------+---------+-----------+----------+------------------------------------
+               Table "generated_virtual_tests.gtest28a"
+ Column |  Type   | Collation | Nullable |           Default           
+--------+---------+-----------+----------+-----------------------------
  b      | integer |           |          | 
  c      | integer |           |          | 
- x      | integer |           |          | generated always as (b * 2) stored
+ x      | integer |           |          | generated always as (b * 2)
 
-                   Table "generated_stored_tests.gtest28b"
- Column |  Type   | Collation | Nullable |              Default               
---------+---------+-----------+----------+------------------------------------
+               Table "generated_virtual_tests.gtest28b"
+ Column |  Type   | Collation | Nullable |           Default           
+--------+---------+-----------+----------+-----------------------------
  b      | integer |           |          | 
  c      | integer |           |          | 
- x      | integer |           |          | generated always as (b * 2) stored
+ x      | integer |           |          | generated always as (b * 2)
 
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index f345d6b45aa..29415191578 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -68,6 +68,9 @@ test: select_into select_distinct select_distinct_on select_implicit select_havi
 # ----------
 test: brin gin gist spgist privileges init_privs security_label collate matview lock replica_identity rowsecurity object_address tablesample groupingsets drop_operator password identity generated_stored join_hash
 
+# TODO: find a place for this (above group is full)
+test: generated_virtual
+
 # ----------
 # Additional BRIN tests
 # ----------
diff --git a/src/test/regress/sql/create_table_like.sql b/src/test/regress/sql/create_table_like.sql
index 4929d373a2f..3ae42a99272 100644
--- a/src/test/regress/sql/create_table_like.sql
+++ b/src/test/regress/sql/create_table_like.sql
@@ -51,7 +51,7 @@ CREATE TABLE test_like_id_3 (LIKE test_like_id_1 INCLUDING IDENTITY);
 SELECT * FROM test_like_id_3;  -- identity was copied and applied
 DROP TABLE test_like_id_1, test_like_id_2, test_like_id_3;
 
-CREATE TABLE test_like_gen_1 (a int, b int GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE test_like_gen_1 (a int, b int GENERATED ALWAYS AS (a * 2) STORED, c int GENERATED ALWAYS AS (a * 3) VIRTUAL);
 \d test_like_gen_1
 INSERT INTO test_like_gen_1 (a) VALUES (1);
 SELECT * FROM test_like_gen_1;
diff --git a/src/test/regress/sql/generated_stored.sql b/src/test/regress/sql/generated_stored.sql
index c18e0e1f655..03ea1954903 100644
--- a/src/test/regress/sql/generated_stored.sql
+++ b/src/test/regress/sql/generated_stored.sql
@@ -1,5 +1,5 @@
 -- sanity check of system catalog
-SELECT attrelid, attname, attgenerated FROM pg_attribute WHERE attgenerated NOT IN ('', 's');
+SELECT attrelid, attname, attgenerated FROM pg_attribute WHERE attgenerated NOT IN ('', 's', 'v');
 
 
 CREATE SCHEMA generated_stored_tests;
diff --git a/src/test/regress/sql/generated_stored.sql b/src/test/regress/sql/generated_virtual.sql
similarity index 76%
copy from src/test/regress/sql/generated_stored.sql
copy to src/test/regress/sql/generated_virtual.sql
index c18e0e1f655..64a0109fd25 100644
--- a/src/test/regress/sql/generated_stored.sql
+++ b/src/test/regress/sql/generated_virtual.sql
@@ -1,55 +1,55 @@
 -- sanity check of system catalog
-SELECT attrelid, attname, attgenerated FROM pg_attribute WHERE attgenerated NOT IN ('', 's');
+SELECT attrelid, attname, attgenerated FROM pg_attribute WHERE attgenerated NOT IN ('', 's', 'v');
 
 
-CREATE SCHEMA generated_stored_tests;
-GRANT USAGE ON SCHEMA generated_stored_tests TO PUBLIC;
-SET search_path = generated_stored_tests;
+CREATE SCHEMA generated_virtual_tests;
+GRANT USAGE ON SCHEMA generated_virtual_tests TO PUBLIC;
+SET search_path = generated_virtual_tests;
 
-CREATE TABLE gtest0 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (55) STORED);
-CREATE TABLE gtest1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE gtest0 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (55) VIRTUAL);
+CREATE TABLE gtest1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL);
 
-SELECT table_name, column_name, column_default, is_nullable, is_generated, generation_expression FROM information_schema.columns WHERE table_schema = 'generated_stored_tests' ORDER BY 1, 2;
+SELECT table_name, column_name, column_default, is_nullable, is_generated, generation_expression FROM information_schema.columns WHERE table_schema = 'generated_virtual_tests' ORDER BY 1, 2;
 
-SELECT table_name, column_name, dependent_column FROM information_schema.column_column_usage WHERE table_schema = 'generated_stored_tests' ORDER BY 1, 2, 3;
+SELECT table_name, column_name, dependent_column FROM information_schema.column_column_usage WHERE table_schema = 'generated_virtual_tests' ORDER BY 1, 2, 3;
 
 \d gtest1
 
 -- duplicate generated
-CREATE TABLE gtest_err_1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED GENERATED ALWAYS AS (a * 3) STORED);
+CREATE TABLE gtest_err_1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL GENERATED ALWAYS AS (a * 3) VIRTUAL);
 
 -- references to other generated columns, including self-references
-CREATE TABLE gtest_err_2a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (b * 2) STORED);
-CREATE TABLE gtest_err_2b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED, c int GENERATED ALWAYS AS (b * 3) STORED);
+CREATE TABLE gtest_err_2a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (b * 2) VIRTUAL);
+CREATE TABLE gtest_err_2b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL, c int GENERATED ALWAYS AS (b * 3) VIRTUAL);
 -- a whole-row var is a self-reference on steroids, so disallow that too
 CREATE TABLE gtest_err_2c (a int PRIMARY KEY,
-    b int GENERATED ALWAYS AS (num_nulls(gtest_err_2c)) STORED);
+    b int GENERATED ALWAYS AS (num_nulls(gtest_err_2c)) VIRTUAL);
 
 -- invalid reference
-CREATE TABLE gtest_err_3 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (c * 2) STORED);
+CREATE TABLE gtest_err_3 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (c * 2) VIRTUAL);
 
 -- generation expression must be immutable
-CREATE TABLE gtest_err_4 (a int PRIMARY KEY, b double precision GENERATED ALWAYS AS (random()) STORED);
+CREATE TABLE gtest_err_4 (a int PRIMARY KEY, b double precision GENERATED ALWAYS AS (random()) VIRTUAL);
 -- ... but be sure that the immutability test is accurate
-CREATE TABLE gtest2 (a int, b text GENERATED ALWAYS AS (a || ' sec') STORED);
+CREATE TABLE gtest2 (a int, b text GENERATED ALWAYS AS (a || ' sec') VIRTUAL);
 DROP TABLE gtest2;
 
 -- cannot have default/identity and generated
-CREATE TABLE gtest_err_5a (a int PRIMARY KEY, b int DEFAULT 5 GENERATED ALWAYS AS (a * 2) STORED);
-CREATE TABLE gtest_err_5b (a int PRIMARY KEY, b int GENERATED ALWAYS AS identity GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE gtest_err_5a (a int PRIMARY KEY, b int DEFAULT 5 GENERATED ALWAYS AS (a * 2) VIRTUAL);
+CREATE TABLE gtest_err_5b (a int PRIMARY KEY, b int GENERATED ALWAYS AS identity GENERATED ALWAYS AS (a * 2) VIRTUAL);
 
 -- reference to system column not allowed in generated column
 -- (except tableoid, which we test below)
-CREATE TABLE gtest_err_6a (a int PRIMARY KEY, b bool GENERATED ALWAYS AS (xmin <> 37) STORED);
+CREATE TABLE gtest_err_6a (a int PRIMARY KEY, b bool GENERATED ALWAYS AS (xmin <> 37) VIRTUAL);
 
 -- various prohibited constructs
-CREATE TABLE gtest_err_7a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (avg(a)) STORED);
-CREATE TABLE gtest_err_7b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (row_number() OVER (ORDER BY a)) STORED);
-CREATE TABLE gtest_err_7c (a int PRIMARY KEY, b int GENERATED ALWAYS AS ((SELECT a)) STORED);
-CREATE TABLE gtest_err_7d (a int PRIMARY KEY, b int GENERATED ALWAYS AS (generate_series(1, a)) STORED);
+CREATE TABLE gtest_err_7a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (avg(a)) VIRTUAL);
+CREATE TABLE gtest_err_7b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (row_number() OVER (ORDER BY a)) VIRTUAL);
+CREATE TABLE gtest_err_7c (a int PRIMARY KEY, b int GENERATED ALWAYS AS ((SELECT a)) VIRTUAL);
+CREATE TABLE gtest_err_7d (a int PRIMARY KEY, b int GENERATED ALWAYS AS (generate_series(1, a)) VIRTUAL);
 
 -- GENERATED BY DEFAULT not allowed
-CREATE TABLE gtest_err_8 (a int PRIMARY KEY, b int GENERATED BY DEFAULT AS (a * 2) STORED);
+CREATE TABLE gtest_err_8 (a int PRIMARY KEY, b int GENERATED BY DEFAULT AS (a * 2) VIRTUAL);
 
 INSERT INTO gtest1 VALUES (1);
 INSERT INTO gtest1 VALUES (2, DEFAULT);  -- ok
@@ -70,7 +70,7 @@ CREATE TABLE gtest_err_8 (a int PRIMARY KEY, b int GENERATED BY DEFAULT AS (a *
 SELECT a, b, b * 2 AS b2 FROM gtest1 ORDER BY a;
 SELECT a, b FROM gtest1 WHERE b = 4 ORDER BY a;
 
--- test that overflow error happens on write
+-- test that overflow error happens on read
 INSERT INTO gtest1 VALUES (2000000000);
 SELECT * FROM gtest1;
 DELETE FROM gtest1 WHERE a = 2000000000;
@@ -93,8 +93,8 @@ CREATE TABLE gtestm (
   id int PRIMARY KEY,
   f1 int,
   f2 int,
-  f3 int GENERATED ALWAYS AS (f1 * 2) STORED,
-  f4 int GENERATED ALWAYS AS (f2 * 2) STORED
+  f3 int GENERATED ALWAYS AS (f1 * 2) VIRTUAL,
+  f4 int GENERATED ALWAYS AS (f2 * 2) VIRTUAL
 );
 INSERT INTO gtestm VALUES (1, 5, 100);
 MERGE INTO gtestm t USING (VALUES (1, 10), (2, 20)) v(id, f1) ON t.id = v.id
@@ -134,22 +134,22 @@ CREATE TABLE gtest1_1 () INHERITS (gtest1);
 
 -- can't have generated column that is a child of normal column
 CREATE TABLE gtest_normal (a int, b int);
-CREATE TABLE gtest_normal_child (a int, b int GENERATED ALWAYS AS (a * 2) STORED) INHERITS (gtest_normal);  -- error
-CREATE TABLE gtest_normal_child (a int, b int GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE gtest_normal_child (a int, b int GENERATED ALWAYS AS (a * 2) VIRTUAL) INHERITS (gtest_normal);  -- error
+CREATE TABLE gtest_normal_child (a int, b int GENERATED ALWAYS AS (a * 2) VIRTUAL);
 ALTER TABLE gtest_normal_child INHERIT gtest_normal;  -- error
 DROP TABLE gtest_normal, gtest_normal_child;
 
 -- test inheritance mismatches between parent and child
 CREATE TABLE gtestx (x int, b int DEFAULT 10) INHERITS (gtest1);  -- error
 CREATE TABLE gtestx (x int, b int GENERATED ALWAYS AS IDENTITY) INHERITS (gtest1);  -- error
-CREATE TABLE gtestx (x int, b int GENERATED ALWAYS AS (a * 22) STORED) INHERITS (gtest1);  -- ok, overrides parent
+CREATE TABLE gtestx (x int, b int GENERATED ALWAYS AS (a * 22) VIRTUAL) INHERITS (gtest1);  -- ok, overrides parent
 \d+ gtestx
 
 CREATE TABLE gtestxx_1 (a int NOT NULL, b int);
 ALTER TABLE gtestxx_1 INHERIT gtest1;  -- error
-CREATE TABLE gtestxx_3 (a int NOT NULL, b int GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE gtestxx_3 (a int NOT NULL, b int GENERATED ALWAYS AS (a * 2) VIRTUAL);
 ALTER TABLE gtestxx_3 INHERIT gtest1;  -- ok
-CREATE TABLE gtestxx_4 (b int GENERATED ALWAYS AS (a * 2) STORED, a int NOT NULL);
+CREATE TABLE gtestxx_4 (b int GENERATED ALWAYS AS (a * 2) VIRTUAL, a int NOT NULL);
 ALTER TABLE gtestxx_4 INHERIT gtest1;  -- ok
 
 -- test multiple inheritance mismatches
@@ -161,28 +161,28 @@ CREATE TABLE gtesty (x int, b int);
 CREATE TABLE gtest1_y () INHERITS (gtest1, gtesty);  -- error
 DROP TABLE gtesty;
 
-CREATE TABLE gtesty (x int, b int GENERATED ALWAYS AS (x * 22) STORED);
+CREATE TABLE gtesty (x int, b int GENERATED ALWAYS AS (x * 22) VIRTUAL);
 CREATE TABLE gtest1_y () INHERITS (gtest1, gtesty);  -- error
-CREATE TABLE gtest1_y (b int GENERATED ALWAYS AS (x + 1) STORED) INHERITS (gtest1, gtesty);  -- ok
+CREATE TABLE gtest1_y (b int GENERATED ALWAYS AS (x + 1) VIRTUAL) INHERITS (gtest1, gtesty);  -- ok
 \d gtest1_y
 
 -- test correct handling of GENERATED column that's only in child
 CREATE TABLE gtestp (f1 int);
-CREATE TABLE gtestc (f2 int GENERATED ALWAYS AS (f1+1) STORED) INHERITS(gtestp);
+CREATE TABLE gtestc (f2 int GENERATED ALWAYS AS (f1+1) VIRTUAL) INHERITS(gtestp);
 INSERT INTO gtestc values(42);
 TABLE gtestc;
 UPDATE gtestp SET f1 = f1 * 10;
 TABLE gtestc;
 DROP TABLE gtestp CASCADE;
 
--- test stored update
-CREATE TABLE gtest3 (a int, b int GENERATED ALWAYS AS (a * 3) STORED);
+-- test update XXX
+CREATE TABLE gtest3 (a int, b int GENERATED ALWAYS AS (a * 3) VIRTUAL);
 INSERT INTO gtest3 (a) VALUES (1), (2), (3), (NULL);
 SELECT * FROM gtest3 ORDER BY a;
 UPDATE gtest3 SET a = 22 WHERE a = 2;
 SELECT * FROM gtest3 ORDER BY a;
 
-CREATE TABLE gtest3a (a text, b text GENERATED ALWAYS AS (a || '+' || a) STORED);
+CREATE TABLE gtest3a (a text, b text GENERATED ALWAYS AS (a || '+' || a) VIRTUAL);
 INSERT INTO gtest3a (a) VALUES ('a'), ('b'), ('c'), (NULL);
 SELECT * FROM gtest3a ORDER BY a;
 UPDATE gtest3a SET a = 'bb' WHERE a = 'b';
@@ -222,12 +222,12 @@ CREATE TABLE gtest3a (a text, b text GENERATED ALWAYS AS (a || '+' || a) STORED)
 SELECT * FROM gtest3 ORDER BY a;
 
 -- null values
-CREATE TABLE gtest2 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (NULL) STORED);
+CREATE TABLE gtest2 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (NULL) VIRTUAL);
 INSERT INTO gtest2 VALUES (1);
 SELECT * FROM gtest2;
 
 -- simple column reference for varlena types
-CREATE TABLE gtest_varlena (a varchar, b varchar GENERATED ALWAYS AS (a) STORED);
+CREATE TABLE gtest_varlena (a varchar, b varchar GENERATED ALWAYS AS (a) VIRTUAL);
 INSERT INTO gtest_varlena (a) VALUES('01234567890123456789');
 INSERT INTO gtest_varlena (a) VALUES(NULL);
 SELECT * FROM gtest_varlena ORDER BY a;
@@ -237,7 +237,7 @@ CREATE TABLE gtest_varlena (a varchar, b varchar GENERATED ALWAYS AS (a) STORED)
 CREATE TYPE double_int as (a int, b int);
 CREATE TABLE gtest4 (
     a int,
-    b double_int GENERATED ALWAYS AS ((a * 2, a * 3)) STORED
+    b double_int GENERATED ALWAYS AS ((a * 2, a * 3)) VIRTUAL
 );
 INSERT INTO gtest4 VALUES (1), (6);
 SELECT * FROM gtest4;
@@ -248,168 +248,168 @@ CREATE TABLE gtest4 (
 -- using tableoid is allowed
 CREATE TABLE gtest_tableoid (
   a int PRIMARY KEY,
-  b bool GENERATED ALWAYS AS (tableoid = 'gtest_tableoid'::regclass) STORED
+  b bool GENERATED ALWAYS AS (tableoid = 'gtest_tableoid'::regclass) VIRTUAL
 );
 INSERT INTO gtest_tableoid VALUES (1), (2);
 ALTER TABLE gtest_tableoid ADD COLUMN
-  c regclass GENERATED ALWAYS AS (tableoid) STORED;
+  c regclass GENERATED ALWAYS AS (tableoid) VIRTUAL;
 SELECT * FROM gtest_tableoid;
 
 -- drop column behavior
-CREATE TABLE gtest10 (a int PRIMARY KEY, b int, c int GENERATED ALWAYS AS (b * 2) STORED);
+CREATE TABLE gtest10 (a int PRIMARY KEY, b int, c int GENERATED ALWAYS AS (b * 2) VIRTUAL);
 ALTER TABLE gtest10 DROP COLUMN b;  -- fails
 ALTER TABLE gtest10 DROP COLUMN b CASCADE;  -- drops c too
 
 \d gtest10
 
-CREATE TABLE gtest10a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE gtest10a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL);
 ALTER TABLE gtest10a DROP COLUMN b;
 INSERT INTO gtest10a (a) VALUES (1);
 
 -- privileges
 CREATE USER regress_user11;
 
-CREATE TABLE gtest11s (a int PRIMARY KEY, b int, c int GENERATED ALWAYS AS (b * 2) STORED);
-INSERT INTO gtest11s VALUES (1, 10), (2, 20);
-GRANT SELECT (a, c) ON gtest11s TO regress_user11;
+CREATE TABLE gtest11v (a int PRIMARY KEY, b int, c int GENERATED ALWAYS AS (b * 2) VIRTUAL);
+INSERT INTO gtest11v VALUES (1, 10), (2, 20);
+GRANT SELECT (a, c) ON gtest11v TO regress_user11;
 
 CREATE FUNCTION gf1(a int) RETURNS int AS $$ SELECT a * 3 $$ IMMUTABLE LANGUAGE SQL;
 REVOKE ALL ON FUNCTION gf1(int) FROM PUBLIC;
 
-CREATE TABLE gtest12s (a int PRIMARY KEY, b int, c int GENERATED ALWAYS AS (gf1(b)) STORED);
-INSERT INTO gtest12s VALUES (1, 10), (2, 20);
+CREATE TABLE gtest12v (a int PRIMARY KEY, b int, c int GENERATED ALWAYS AS (gf1(b)) VIRTUAL);
+INSERT INTO gtest12v VALUES (1, 10), (2, 20);
 GRANT SELECT (a, c) ON gtest12s TO regress_user11;
 
 SET ROLE regress_user11;
-SELECT a, b FROM gtest11s;  -- not allowed
-SELECT a, c FROM gtest11s;  -- allowed
+SELECT a, b FROM gtest11v;  -- not allowed
+SELECT a, c FROM gtest11v;  -- allowed
 SELECT gf1(10);  -- not allowed
-SELECT a, c FROM gtest12s;  -- allowed
+SELECT a, c FROM gtest12v;  -- not allowed; TODO: ought to be allowed
 RESET ROLE;
 
 DROP FUNCTION gf1(int);  -- fail
-DROP TABLE gtest11s, gtest12s;
+DROP TABLE gtest11v, gtest12v;
 DROP FUNCTION gf1(int);
 DROP USER regress_user11;
 
 -- check constraints
-CREATE TABLE gtest20 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED CHECK (b < 50));
+CREATE TABLE gtest20 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL CHECK (b < 50));
 INSERT INTO gtest20 (a) VALUES (10);  -- ok
 INSERT INTO gtest20 (a) VALUES (30);  -- violates constraint
 
 ALTER TABLE gtest20 ALTER COLUMN b SET EXPRESSION AS (a * 100);  -- violates constraint
 ALTER TABLE gtest20 ALTER COLUMN b SET EXPRESSION AS (a * 3);  -- ok
 
-CREATE TABLE gtest20a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE gtest20a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL);
 INSERT INTO gtest20a (a) VALUES (10);
 INSERT INTO gtest20a (a) VALUES (30);
 ALTER TABLE gtest20a ADD CHECK (b < 50);  -- fails on existing row
 
-CREATE TABLE gtest20b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED);
+CREATE TABLE gtest20b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL);
 INSERT INTO gtest20b (a) VALUES (10);
 INSERT INTO gtest20b (a) VALUES (30);
 ALTER TABLE gtest20b ADD CONSTRAINT chk CHECK (b < 50) NOT VALID;
 ALTER TABLE gtest20b VALIDATE CONSTRAINT chk;  -- fails on existing row
 
 -- not-null constraints
-CREATE TABLE gtest21a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (nullif(a, 0)) STORED NOT NULL);
+CREATE TABLE gtest21a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (nullif(a, 0)) VIRTUAL NOT NULL);
 INSERT INTO gtest21a (a) VALUES (1);  -- ok
 INSERT INTO gtest21a (a) VALUES (0);  -- violates constraint
 
-CREATE TABLE gtest21b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (nullif(a, 0)) STORED);
-ALTER TABLE gtest21b ALTER COLUMN b SET NOT NULL;
+CREATE TABLE gtest21b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (nullif(a, 0)) VIRTUAL);
+ALTER TABLE gtest21b ALTER COLUMN b SET NOT NULL;  -- FIXME
 INSERT INTO gtest21b (a) VALUES (1);  -- ok
 INSERT INTO gtest21b (a) VALUES (0);  -- violates constraint
-ALTER TABLE gtest21b ALTER COLUMN b DROP NOT NULL;
+ALTER TABLE gtest21b ALTER COLUMN b DROP NOT NULL;  -- FIXME
 INSERT INTO gtest21b (a) VALUES (0);  -- ok now
 
 -- index constraints
-CREATE TABLE gtest22a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a / 2) STORED UNIQUE);
-INSERT INTO gtest22a VALUES (2);
-INSERT INTO gtest22a VALUES (3);
-INSERT INTO gtest22a VALUES (4);
-CREATE TABLE gtest22b (a int, b int GENERATED ALWAYS AS (a / 2) STORED, PRIMARY KEY (a, b));
-INSERT INTO gtest22b VALUES (2);
-INSERT INTO gtest22b VALUES (2);
+CREATE TABLE gtest22a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a / 2) VIRTUAL UNIQUE);
+--INSERT INTO gtest22a VALUES (2);
+--INSERT INTO gtest22a VALUES (3);
+--INSERT INTO gtest22a VALUES (4);
+CREATE TABLE gtest22b (a int, b int GENERATED ALWAYS AS (a / 2) VIRTUAL, PRIMARY KEY (a, b));
+--INSERT INTO gtest22b VALUES (2);
+--INSERT INTO gtest22b VALUES (2);
 
 -- indexes
-CREATE TABLE gtest22c (a int, b int GENERATED ALWAYS AS (a * 2) STORED);
-CREATE INDEX gtest22c_b_idx ON gtest22c (b);
-CREATE INDEX gtest22c_expr_idx ON gtest22c ((b * 3));
-CREATE INDEX gtest22c_pred_idx ON gtest22c (a) WHERE b > 0;
-\d gtest22c
-
-INSERT INTO gtest22c VALUES (1), (2), (3);
-SET enable_seqscan TO off;
-SET enable_bitmapscan TO off;
-EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b = 4;
-SELECT * FROM gtest22c WHERE b = 4;
-EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b * 3 = 6;
-SELECT * FROM gtest22c WHERE b * 3 = 6;
-EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
-SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
-
-ALTER TABLE gtest22c ALTER COLUMN b SET EXPRESSION AS (a * 4);
-ANALYZE gtest22c;
-EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b = 8;
-SELECT * FROM gtest22c WHERE b = 8;
-EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b * 3 = 12;
-SELECT * FROM gtest22c WHERE b * 3 = 12;
-EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
-SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
-RESET enable_seqscan;
-RESET enable_bitmapscan;
+CREATE TABLE gtest22c (a int, b int GENERATED ALWAYS AS (a * 2) VIRTUAL);
+--CREATE INDEX gtest22c_b_idx ON gtest22c (b);
+--CREATE INDEX gtest22c_expr_idx ON gtest22c ((b * 3));
+--CREATE INDEX gtest22c_pred_idx ON gtest22c (a) WHERE b > 0;
+--\d gtest22c
+
+--INSERT INTO gtest22c VALUES (1), (2), (3);
+--SET enable_seqscan TO off;
+--SET enable_bitmapscan TO off;
+--EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b = 4;
+--SELECT * FROM gtest22c WHERE b = 4;
+--EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b * 3 = 6;
+--SELECT * FROM gtest22c WHERE b * 3 = 6;
+--EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
+--SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
+
+--ALTER TABLE gtest22c ALTER COLUMN b SET EXPRESSION AS (a * 4);
+--ANALYZE gtest22c;
+--EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b = 8;
+--SELECT * FROM gtest22c WHERE b = 8;
+--EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b * 3 = 12;
+--SELECT * FROM gtest22c WHERE b * 3 = 12;
+--EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
+--SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
+--RESET enable_seqscan;
+--RESET enable_bitmapscan;
 
 -- foreign keys
 CREATE TABLE gtest23a (x int PRIMARY KEY, y int);
-INSERT INTO gtest23a VALUES (1, 11), (2, 22), (3, 33);
+--INSERT INTO gtest23a VALUES (1, 11), (2, 22), (3, 33);
 
-CREATE TABLE gtest23x (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED REFERENCES gtest23a (x) ON UPDATE CASCADE);  -- error
-CREATE TABLE gtest23x (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED REFERENCES gtest23a (x) ON DELETE SET NULL);  -- error
+CREATE TABLE gtest23x (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL REFERENCES gtest23a (x) ON UPDATE CASCADE);  -- error
+CREATE TABLE gtest23x (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL REFERENCES gtest23a (x) ON DELETE SET NULL);  -- error
 
-CREATE TABLE gtest23b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED REFERENCES gtest23a (x));
-\d gtest23b
+CREATE TABLE gtest23b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) VIRTUAL REFERENCES gtest23a (x));
+--\d gtest23b
 
-INSERT INTO gtest23b VALUES (1);  -- ok
-INSERT INTO gtest23b VALUES (5);  -- error
-ALTER TABLE gtest23b ALTER COLUMN b SET EXPRESSION AS (a * 5); -- error
-ALTER TABLE gtest23b ALTER COLUMN b SET EXPRESSION AS (a * 1); -- ok
+--INSERT INTO gtest23b VALUES (1);  -- ok
+--INSERT INTO gtest23b VALUES (5);  -- error
+--ALTER TABLE gtest23b ALTER COLUMN b SET EXPRESSION AS (a * 5); -- error
+--ALTER TABLE gtest23b ALTER COLUMN b SET EXPRESSION AS (a * 1); -- ok
 
-DROP TABLE gtest23b;
-DROP TABLE gtest23a;
+--DROP TABLE gtest23b;
+--DROP TABLE gtest23a;
 
-CREATE TABLE gtest23p (x int, y int GENERATED ALWAYS AS (x * 2) STORED, PRIMARY KEY (y));
-INSERT INTO gtest23p VALUES (1), (2), (3);
+CREATE TABLE gtest23p (x int, y int GENERATED ALWAYS AS (x * 2) VIRTUAL, PRIMARY KEY (y));
+--INSERT INTO gtest23p VALUES (1), (2), (3);
 
 CREATE TABLE gtest23q (a int PRIMARY KEY, b int REFERENCES gtest23p (y));
-INSERT INTO gtest23q VALUES (1, 2);  -- ok
-INSERT INTO gtest23q VALUES (2, 5);  -- error
+--INSERT INTO gtest23q VALUES (1, 2);  -- ok
+--INSERT INTO gtest23q VALUES (2, 5);  -- error
 
 -- domains
 CREATE DOMAIN gtestdomain1 AS int CHECK (VALUE < 10);
-CREATE TABLE gtest24 (a int PRIMARY KEY, b gtestdomain1 GENERATED ALWAYS AS (a * 2) STORED);
-INSERT INTO gtest24 (a) VALUES (4);  -- ok
-INSERT INTO gtest24 (a) VALUES (6);  -- error
+CREATE TABLE gtest24 (a int PRIMARY KEY, b gtestdomain1 GENERATED ALWAYS AS (a * 2) VIRTUAL);
+--INSERT INTO gtest24 (a) VALUES (4);  -- ok
+--INSERT INTO gtest24 (a) VALUES (6);  -- error
 
 -- typed tables (currently not supported)
 CREATE TYPE gtest_type AS (f1 integer, f2 text, f3 bigint);
-CREATE TABLE gtest28 OF gtest_type (f1 WITH OPTIONS GENERATED ALWAYS AS (f2 *2) STORED);
+CREATE TABLE gtest28 OF gtest_type (f1 WITH OPTIONS GENERATED ALWAYS AS (f2 *2) VIRTUAL);
 DROP TYPE gtest_type CASCADE;
 
 -- partitioning cases
 CREATE TABLE gtest_parent (f1 date NOT NULL, f2 bigint, f3 bigint) PARTITION BY RANGE (f1);
 CREATE TABLE gtest_child PARTITION OF gtest_parent (
-    f3 WITH OPTIONS GENERATED ALWAYS AS (f2 * 2) STORED
+    f3 WITH OPTIONS GENERATED ALWAYS AS (f2 * 2) VIRTUAL
 ) FOR VALUES FROM ('2016-07-01') TO ('2016-08-01'); -- error
-CREATE TABLE gtest_child (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) STORED);
+CREATE TABLE gtest_child (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) VIRTUAL);
 ALTER TABLE gtest_parent ATTACH PARTITION gtest_child FOR VALUES FROM ('2016-07-01') TO ('2016-08-01'); -- error
 DROP TABLE gtest_parent, gtest_child;
 
-CREATE TABLE gtest_parent (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE (f1);
+CREATE TABLE gtest_parent (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) VIRTUAL) PARTITION BY RANGE (f1);
 CREATE TABLE gtest_child PARTITION OF gtest_parent
   FOR VALUES FROM ('2016-07-01') TO ('2016-08-01');  -- inherits gen expr
 CREATE TABLE gtest_child2 PARTITION OF gtest_parent (
-    f3 WITH OPTIONS GENERATED ALWAYS AS (f2 * 22) STORED  -- overrides gen expr
+    f3 WITH OPTIONS GENERATED ALWAYS AS (f2 * 22) VIRTUAL  -- overrides gen expr
 ) FOR VALUES FROM ('2016-08-01') TO ('2016-09-01');
 CREATE TABLE gtest_child3 PARTITION OF gtest_parent (
     f3 DEFAULT 42  -- error
@@ -426,7 +426,7 @@ CREATE TABLE gtest_child3 (f1 date NOT NULL, f2 bigint, f3 bigint DEFAULT 42);
 CREATE TABLE gtest_child3 (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS IDENTITY);
 ALTER TABLE gtest_parent ATTACH PARTITION gtest_child3 FOR VALUES FROM ('2016-09-01') TO ('2016-10-01'); -- error
 DROP TABLE gtest_child3;
-CREATE TABLE gtest_child3 (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 33) STORED);
+CREATE TABLE gtest_child3 (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 33) VIRTUAL);
 ALTER TABLE gtest_parent ATTACH PARTITION gtest_child3 FOR VALUES FROM ('2016-09-01') TO ('2016-10-01');
 \d gtest_child
 \d gtest_child2
@@ -457,21 +457,21 @@ CREATE TABLE gtest_child3 (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWA
 -- we leave these tables around for purposes of testing dump/reload/upgrade
 
 -- generated columns in partition key (not allowed)
-CREATE TABLE gtest_part_key (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE (f3);
-CREATE TABLE gtest_part_key (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE ((f3 * 3));
+CREATE TABLE gtest_part_key (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) VIRTUAL) PARTITION BY RANGE (f3);
+CREATE TABLE gtest_part_key (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) VIRTUAL) PARTITION BY RANGE ((f3 * 3));
 
 -- ALTER TABLE ... ADD COLUMN
 CREATE TABLE gtest25 (a int PRIMARY KEY);
 INSERT INTO gtest25 VALUES (3), (4);
-ALTER TABLE gtest25 ADD COLUMN b int GENERATED ALWAYS AS (a * 2) STORED, ALTER COLUMN b SET EXPRESSION AS (a * 3);
+ALTER TABLE gtest25 ADD COLUMN b int GENERATED ALWAYS AS (a * 2) VIRTUAL, ALTER COLUMN b SET EXPRESSION AS (a * 3);
 SELECT * FROM gtest25 ORDER BY a;
-ALTER TABLE gtest25 ADD COLUMN x int GENERATED ALWAYS AS (b * 4) STORED;  -- error
-ALTER TABLE gtest25 ADD COLUMN x int GENERATED ALWAYS AS (z * 4) STORED;  -- error
+ALTER TABLE gtest25 ADD COLUMN x int GENERATED ALWAYS AS (b * 4) VIRTUAL;  -- error
+ALTER TABLE gtest25 ADD COLUMN x int GENERATED ALWAYS AS (z * 4) VIRTUAL;  -- error
 ALTER TABLE gtest25 ADD COLUMN c int DEFAULT 42,
-  ADD COLUMN x int GENERATED ALWAYS AS (c * 4) STORED;
+  ADD COLUMN x int GENERATED ALWAYS AS (c * 4) VIRTUAL;
 ALTER TABLE gtest25 ADD COLUMN d int DEFAULT 101;
 ALTER TABLE gtest25 ALTER COLUMN d SET DATA TYPE float8,
-  ADD COLUMN y float8 GENERATED ALWAYS AS (d * 4) STORED;
+  ADD COLUMN y float8 GENERATED ALWAYS AS (d * 4) VIRTUAL;
 SELECT * FROM gtest25 ORDER BY a;
 \d gtest25
 
@@ -479,7 +479,7 @@ CREATE TABLE gtest25 (a int PRIMARY KEY);
 CREATE TABLE gtest27 (
     a int,
     b int,
-    x int GENERATED ALWAYS AS ((a + b) * 2) STORED
+    x int GENERATED ALWAYS AS ((a + b) * 2) VIRTUAL
 );
 INSERT INTO gtest27 (a, b) VALUES (3, 7), (4, 11);
 ALTER TABLE gtest27 ALTER COLUMN a TYPE text;  -- error
@@ -493,7 +493,7 @@ CREATE TABLE gtest27 (
   DROP COLUMN x,
   ALTER COLUMN a TYPE bigint,
   ALTER COLUMN b TYPE bigint,
-  ADD COLUMN x bigint GENERATED ALWAYS AS ((a + b) * 2) STORED;
+  ADD COLUMN x bigint GENERATED ALWAYS AS ((a + b) * 2) VIRTUAL;
 \d gtest27
 -- Ideally you could just do this, but not today (and should x change type?):
 ALTER TABLE gtest27
@@ -505,7 +505,7 @@ CREATE TABLE gtest27 (
 -- ALTER TABLE ... ALTER COLUMN ... DROP EXPRESSION
 CREATE TABLE gtest29 (
     a int,
-    b int GENERATED ALWAYS AS (a * 2) STORED
+    b int GENERATED ALWAYS AS (a * 2) VIRTUAL
 );
 INSERT INTO gtest29 (a) VALUES (3), (4);
 SELECT * FROM gtest29;
@@ -532,7 +532,7 @@ CREATE TABLE gtest29 (
 -- with inheritance
 CREATE TABLE gtest30 (
     a int,
-    b int GENERATED ALWAYS AS (a * 2) STORED
+    b int GENERATED ALWAYS AS (a * 2) VIRTUAL
 );
 CREATE TABLE gtest30_1 () INHERITS (gtest30);
 ALTER TABLE gtest30 ALTER COLUMN b DROP EXPRESSION;
@@ -541,7 +541,7 @@ CREATE TABLE gtest30_1 () INHERITS (gtest30);
 DROP TABLE gtest30 CASCADE;
 CREATE TABLE gtest30 (
     a int,
-    b int GENERATED ALWAYS AS (a * 2) STORED
+    b int GENERATED ALWAYS AS (a * 2) VIRTUAL
 );
 CREATE TABLE gtest30_1 () INHERITS (gtest30);
 ALTER TABLE ONLY gtest30 ALTER COLUMN b DROP EXPRESSION;  -- error
@@ -552,7 +552,7 @@ CREATE TABLE gtest30_1 () INHERITS (gtest30);
 -- triggers
 CREATE TABLE gtest26 (
     a int PRIMARY KEY,
-    b int GENERATED ALWAYS AS (a * 2) STORED
+    b int GENERATED ALWAYS AS (a * 2) VIRTUAL
 );
 
 CREATE FUNCTION gtest_trigger_func() RETURNS trigger
@@ -614,6 +614,9 @@ CREATE TRIGGER gtest4 AFTER INSERT OR UPDATE ON gtest26
 DROP TRIGGER gtest2 ON gtest26;
 DROP TRIGGER gtest3 ON gtest26;
 
+-- check disallowed modification of virtual columns
+-- TODO
+
 -- Check that an UPDATE of "a" fires the trigger for UPDATE OF b, per
 -- SQL standard.
 CREATE FUNCTION gtest_trigger_func3() RETURNS trigger
@@ -667,7 +670,7 @@ CREATE TABLE gtest28a (
   a int,
   b int,
   c int,
-  x int GENERATED ALWAYS AS (b * 2) STORED
+  x int GENERATED ALWAYS AS (b * 2) VIRTUAL
 );
 
 ALTER TABLE gtest28a DROP COLUMN a;
diff --git a/src/test/subscription/t/011_generated.pl b/src/test/subscription/t/011_generated.pl
index 8b2e5f4708e..faee155daa7 100644
--- a/src/test/subscription/t/011_generated.pl
+++ b/src/test/subscription/t/011_generated.pl
@@ -21,11 +21,11 @@
 my $publisher_connstr = $node_publisher->connstr . ' dbname=postgres';
 
 $node_publisher->safe_psql('postgres',
-	"CREATE TABLE tab1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED)"
+	"CREATE TABLE tab1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED, c int GENERATED ALWAYS AS (a * 3) VIRTUAL)"
 );
 
 $node_subscriber->safe_psql('postgres',
-	"CREATE TABLE tab1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 22) STORED, c int)"
+	"CREATE TABLE tab1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 22) STORED, c int GENERATED ALWAYS AS (a * 33) VIRTUAL, d int)"
 );
 
 # data for initial sync
@@ -42,10 +42,10 @@
 # Wait for initial sync of all subscriptions
 $node_subscriber->wait_for_subscription_sync;
 
-my $result = $node_subscriber->safe_psql('postgres', "SELECT a, b FROM tab1");
-is( $result, qq(1|22
-2|44
-3|66), 'generated columns initial sync');
+my $result = $node_subscriber->safe_psql('postgres', "SELECT a, b, c FROM tab1");
+is( $result, qq(1|22|33
+2|44|66
+3|66|99), 'generated columns initial sync');
 
 # data to replicate
 
@@ -56,11 +56,11 @@
 $node_publisher->wait_for_catchup('sub1');
 
 $result = $node_subscriber->safe_psql('postgres', "SELECT * FROM tab1");
-is( $result, qq(1|22|
-2|44|
-3|66|
-4|88|
-6|132|), 'generated columns replicated');
+is( $result, qq(1|22|33|
+2|44|66|
+3|66|99|
+4|88|132|
+6|132|198|), 'generated columns replicated');
 
 # try it with a subscriber-side trigger
 
@@ -69,7 +69,7 @@
 CREATE FUNCTION tab1_trigger_func() RETURNS trigger
 LANGUAGE plpgsql AS $$
 BEGIN
-  NEW.c := NEW.a + 10;
+  NEW.d := NEW.a + 10;
   RETURN NEW;
 END $$;
 
@@ -88,12 +88,12 @@ BEGIN
 
 $result =
   $node_subscriber->safe_psql('postgres', "SELECT * FROM tab1 ORDER BY 1");
-is( $result, qq(1|22|
-2|44|
-3|66|
-4|88|
-6|132|
-8|176|18
-9|198|19), 'generated columns replicated with trigger');
+is( $result, qq(1|22|33|
+2|44|66|
+3|66|99|
+4|88|132|
+6|132|198|
+8|176|264|18
+9|198|297|19), 'generated columns replicated with trigger');
 
 done_testing();
-- 
2.44.0



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2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
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2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v29 3/6] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v30 3/6] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v31 3/6] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2019-02-01 10:41 [PATCH v33 3/5] Subscripting for jsonb erthalion <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v40 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v38] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v39] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v43 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v48 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v42 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v41 1/2] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v44 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v49 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v46 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2020-12-18 16:19 [PATCH v45 1/3] Subscripting for jsonb Dmitrii Dolgov <[email protected]>
2024-04-29 08:23 Virtual generated columns Peter Eisentraut <[email protected]>

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